How did attitudes of German citizens toward Hitler and the Nazi Party change over the course of the pre-war and the post-war periods?

From 1934 to 1943 we see all the hallmarks of charismatic leadership and a steady rise in popularity of the leader, the party and the regime.

Quantitative data on this is fragmentary, not in the form of reliable opinion polls we expect from a modern newscast, but do not get there either. Qualitative data shows a seemingly consistent picture of support right to the end.

After 1945 that changed considerably in disassociating Germany and the Germans – in the minds of Germans at least — from a lost war and the accompanying atrocities in crime and policy. While the majority kept most of the central themes internalised the larger part constructed a delusion: an image of demonic possession that was imparted by the 'evil aliens' of Nazis suddenly controlling the minds of the people who were then claiming to "have just followed orders".

We have very few direct measures of public approval like it is sometimes theorised to be expressed in voting behaviour.

That is despite some people working under Goebbels having studied with Gallup (later founding the leading research center in Germany for demoscopy).

What we do have are aggregate indirect measures. If real 'political crimes', brought forward as expressing dissent, sabotaging the system, spreading contrarian news, trash talking at the pub etc. are counted than the police, Gestapo etc recorded these acts, sent spies into bars persecuted and prosecuted those 'activists'. These numbers fall from 1933/34 to an impressive low in the early 40s. The Germans loved Hitler. Not all of them, but the very vast majority.

That 'real crimes' is meant to convey a certain lower bound of actual dissent. Minus completely made-up charges this establishes that 100% approval was never reality. As it is just a rough indicator of several, you are still right in principle. Grumbling dissent was effectively silenced to a degree. This should not be misread as "numbers of convictions → percent of dissenters".

Older studies, still too many more recent ones, tend to focus on the unreliability and obviously manipulative tendencies of the internal party public opinion reporting system (like — Aryeh L. Unger: "The Public Opinion Reports of the Nazi Party", The Public Opinion Quarterly, Vol. 29, No. 4 (Winter, 1965–1966), pp. 565–582. That is incomplete in itself. There are more comprehensive approaches available (like — Ian Kershaw: "Popular Opinion and Political Dissent in the Third Reich: Bavaria 1933-1945. Oxford: Clarendon Press, 1983." review.)

Mainly in the beginning sheer terror was seen in the streets with SA-men patrolling with regular police, both beating everyone they disliked, sending them to prison, torture or 'camps'. But that was toned down, the SA almost disenfranchised and much more subtle measures of oppression installed. Of course the propaganda ramped up as well, together with the real perks offered to all those that were to be part of the Volksgemeinschaft.

People really liked Germany 'getting Rhineland, Saarland, Austria, Sudetenland, CSR'. There was a short dip in popularity when the hot war started, but that faded with every victory in Poland.

Especially when France fell Hitler could have declared himself God's newborn. The social benefits on the interior front were also of quite some standard — and continued to rise until things turned sour in Soviet Russia.

Get a job, get a May-day celebration to honour your contribution as a worker, get food in times of at first poverty, then continue to be fed when starting a war and rationing. Get free copy of Mein Kampf, get a piano cheap from previous Jewish owner, or a flat or house, go on paid vacation, enjoy the marches and speeches, Kraft durch Freude is there for you. Movies are at a height, providing joyous escapism, all media constantly tell you how great you are because of being a member of German society and the Aryan race. Who really cares that 'others' have trouble, including being killed for non-sensible reason? Who knew that the perks were on unsolid foundations, betrayal, money laundering, deceit and corruption. Who could really foresee that a war might not only be won, but also lost?

By 1939 the motto "Germany is Hitler, Hitler is Germany" became reality.

The Time of the Blitz Wars: The High Point of Popularity 1940-1941 — Kershaw, 1987

After 1942, and still more in 44, dissenting voices became more often heard, representing a small trend:

"The Führer has it easy, he has no family to take care of. If everything goes wrong with the war, he lets us sit in the dirt and shoots a bullet through his head."
— Woman in a Schweinfurt air-raid shelter, April 1944
"If it had been known in 1933 that events would come to such a head, Hitler would never have been elected."
— A German in March 1945

— Ian Kershaw: "The Hitler Myth. Image and Reality in the Third Reich", Oxford University Press, Oxford, 1987.

The dynamics of military success translating into favourable popular opinion:

German troops had occupied Prague on March 15 of that year. Hermann Voss, a professor of anatomy who was later the recipient of numerous honors in Communist East Germany, noted in his diary:

“Charles University—the oldest German university and the mother of the one in Leipzig—once again in German hands! It’s hard to believe. What a blow for the Slavs and what a boon for us. We are living in a great age and should feel privileged to experience such things. What does it matter if butter is in short supply, coffee is sometimes unavailable, or you sometimes have to do one thing or another that you don’t completely approve of? Weighed against such progress, these problems are laughably trivial."

The Deutsche Steuer-Zeitung, a leading tax periodical, reported:

“The revenues of the excise tax levied on Jews are going exclusively to the Reich, which will devote them to its general tasks and, in that sense, to the benefit of the German people.” The Security Service, perhaps overstating things, noted that, in contrast to the pogroms, the “atonement payment met with approval throughout the populace.”

The top officials in the Finance Ministry were normally too realistic to approve such handouts. But in the wake of Germany’s triumph over France, they convinced themselves that they could afford to be generous, “provided,” as Deputy Finance Minister Fritz Reinhardt wrote to his colleagues:

“the war ends in 1940.” […]“It will surely make a strong public impression in Germany and abroad if we can do without war taxes in a gigantic war such as this.”

“I ask you to ensure that the measures to be taken do not lessen the existing legal purchasing capacity of troops transferred west, especially from the Eastern Front.”

Only when the war began to turn against Germany did Göring feel compelled to stop encouraging private plunder. On May 15, 1944, he gave in to pressure from the Finance and Food Ministries and prohibited “the import of flour, shortening, and meat from the occupied territories.” But the edict was never carried out for fear of popular disapproval. In October, the Finance Ministry noted that because of the worsening military situation “the implementation measures for the prohibition edict were not yet in force.”

The third fundamental pillar of Hitler’s popular support was his promise of equality for all members of the racially defined Volk. In the policies of wartime socialism that came into effect as of September 1, 1939, many Germans saw a credible vision of a more just social order. The war accelerated the obliteration of class barriers. The Nazi leadership was at pains to ensure that

“in these times of shortages every individual Volk comrade will be provided for equally with the necessities of life, regardless of his social position and income.”

The only privileges were for people who did particularly strenuous physical labor or had special needs. In early 1940, an observer from the Social Democratic Party reported from Berlin:

“The working classes thoroughly welcome the fact that ‘the better off’ have, in practical terms, ceased to be that.”

Egalitarian rationing policies increased the popularity of the regime.

The cover for this book shows the genuine affection people had:

The inside of that book lists the rise and fall of public support.

— Götz Aly: "Hitler’s Beneficiaries, Plunder, Racial War, And The Nazi Welfare State", Metropolitan BooksNew York, 2007, (Review) Quotes above here from that book.

They cared quite much for public opinion and did try to find out. Aktion T4 was shut down because of public protest. The form the Endlösung took was heavily influenced by designing it outwardly so that plausible deniability of the act was an option (so they thought) for the population. They used mainly indirect means to measure the big support & approval that continually rose until 1942. It wasn't all stick, they also ate a lot of carrots. From 1935–1943, the "majority of the public was with them". That is a conservative timeframe.

On January 30, 1933, hearing about the celebrations for Hitler’s assumption of power, Erich Ebermayer remarked bitterly in his diary, “We are the losers, definitely the losers.” Learning of the Nuremberg Laws in 1935, which made Jews non-citizens, he raged, “hate is sown a million-fold.” Yet in March 1938, he wept for joy at the Anschluss with Austria: “Not to want it just because it has been achieved by Hitler would be folly.”

Peter Fritzsche deciphers the puzzle of Nazism’s ideological grip. Its basic appeal lay in the Volksgemeinschaft — a “people’s community” that appealed to Germans to be part of a great project to redress the wrongs of the Versailles treaty, make the country strong and vital, and rid the body politic of unhealthy elements. The goal was to create a new national and racial self-consciousness among Germans. For Germany to live, others—especially Jews—had to die.

Diaries and letters reveal Germans’ fears, desires, and reservations, while showing how Nazi concepts saturated everyday life. Fritzsche examines the efforts of Germans to adjust to new racial identities, to believe in the necessity of war, to accept the dynamic of unconditional destruction—in short, to become Nazis.

— Peter Fritzsche: "Life and Death in the Third Reich", Belknap Press, 2008.

Looking through the letters, diaries and memoirs provides another angle:

The initial success of the German army in Russia is proof enough for Manfred von K. that the Nazi cause is just. On July 18, 1941, he writes:

“It is amazing how everything works. Sometimes one doesn’t dare believe in the mathematically precise work of our leadership, but the law of providence has always been with us.”

But as time and the war churn on, his ideology about “Tartars, Jews and Asian peoples” is gradually replaced by a grudging respect for the Soviet army. “In this campaign superlatives were truly achieved,” he observes, “because the enemy fights back quite differently in its toughness and obstinacy than the French and English in the West.”

— Frederic C. Tubach & Sally Patterson Tubach: "German Voices: Memories of Life during Hitler's Third Reich", University of California Press, 2011.

The only remarkable thing about this would seem to be that the years between 1935 and 1942 appear as 'quiet' and 'normal' times—and this in the recollections of inhabitants of a working-class region where in the first years of dictatorship the labour movement suffered the fiercest persecution.

— Richard Bessel: "Life In The Third Reich", Oxford Univesity Press, 1987.

That changed outwardly at the beginning of 1945.

When a British, American or Soviet soldier entered a village or city, some people killed themselves, as life was now 'senseless without Nazi greatness'. Most were eager to express that they all 'were in the resistance' and 'knew nothing' of any brutality, war crimes, genocide — even when questioned about that while living in a former Jewish home.

Most strikingly this is illustrated with the late, very late attempts of meaningful military internal opposition. The alleged head of the conspiracy operation Stauffenberg was an antisemite dyed in the wool, writing in contempt about all the Untermenschen he met while burning down Eastern Europe:

"The population is an incredible mob, very many Jews and very many mixed people. A people, which only feels comfortable under the whip. The thousands of prisoners will do our agriculture quite good. In Germany they are certainly good to use, hard-working, willing and frugal."

Among Germans…

The Consensus Holds Social support for Hitler and for National Socialism steadily eroded as the war encroached more and more into Germany, and many people were certainly fed up. What is remarkable, however, was how resilient public opinion was, and, in spite of one defeat or major setback after the next, the surveyors of opinion found innumerable statements to indicate that morale held, in the sense that many people from all ranks of life were willing to continue the fight, even in the face of great hardship. Thus, after the Normandy invasion in June 1944, there were widespread signs of a positively exuberant optimism and some people yearned to get their hands on Allied troops.

An even greater show of support for Hitler, virulent hatred of the conspirators, and expressed willingness to shoulder more burdens followed the attempt on his life on 20 July 1944. His explanation of the attempted coup, along with the use of the V-1 flying bombs and V-2 rockets—retaliatory ‘miracle weapons’—served only to renew the public’s faith in his ability to see them through. Opinion reports stated that ‘almost everywhere the bonding to the Führer is deepened and the trust in the leadership strengthened’.

Historian Marlis Steinert, who notes these trends, adds that there was nothing less than ‘an astonishingly positive reception’ to Hitler’s New Year’s proclamation for 1945 and his confidence in victory. She and several others who have studied public opinion closely, have tended to magnify the ‘negatives’, like signs of dissolution, loss of faith, and the collapse of morale. However, while the mood and attitude of the people certainly shifted with the military or political situation, many people, and not just the died-in-the-wool Nazis, showed themselves anxious to interpret events in the most optimistic way possible.

The last Nazi opinion reports from Berlin in March 1945 contain evidence that many citizens finally began to question propaganda stories and the more outlandish claims, but that many still showed ‘a good and confident attitude’. If the pessimists and defeatists were in the majority, the Nazi reporters were of the view that the balance would shift back if only the Wehrmacht could show an important victory. Certainly these last glimpses of popular opinion showed signs that people were losing faith, like three women who scoffed at a sign with the words of inspiration that Berlin ‘works, fights, and stands’, placed in the windows of Berlin’s famous department store, the Kaufhaus des Westens.

We also find remarks scattered in these last reports that suggest what Germans were saying among themselves. Two workers in Spandau-West were overheard by the opinion surveyors as saying ‘that we have only ourselves to blame for this war because we treated the Jews so badly. We shouldn’t be too surprised, if they now do the same thing to us.’ These workers acknowledged Germany’s persecution of the Jews, but there are no indications they felt any remorse. They were prepared for the inevitable outcome and believed, as Hitler had prophesied, that they were experiencing the retaliation of the Jews and their influential friends around the world. The Nazi reporter who overheard this exchange noted that ‘similar observations now are often heard’.

Such fragmentary evidence suggests that Nazi allegations over the years that the Jews and some sort of conspiracy caused the war had taken root. In fact during the last two years of the war, letters (including some from academics) were sent to the Ministry of Propaganda suggesting that the Jews remaining in Germany be collected at likely bombing targets. The number killed would be publicized after each raid. One letter said that even if this did not work to stop the Allied flyers, at least many Jews would be exterminated. Another suggestion was to threaten the Americans and British that tenfold the number of Jews would be shot for civilians killed in a given bombing raid.

— Robert Gellately: "Backing Hitler. Consent and Coercion in Nazi Germany.", Oxford University Press, 2001, p253.

That outward expression of disgust after the war towards: Nazis, their party, politics and principles after the war was just lying. Inwardly a big proportion of people continued to approve of most actions, citing a few mistakes, and even "if only Hitler knew that", or "he built the Autobahn". The only real downside for all of those is still just that a war was lost. That is never really popular. Today a party full of genuine Nazis and an official policy to disregard 12 years of Nazi-regime as a 'bird's dropping' compared to '1000 years of history', the voting approval rating of undisguised Nazi positions reaches 80 seats in parliament again.

That is just in accordance with what happened directly after the war.

Q Did people who voted for the Nazis in 1933 later express regret about it?
After the war, was there shaming from Germans who didn't vote the Nazis towards those who did?

Some did so. But for the most part and in both Germanies the former Nazis just became jurists, doctors, civil servants, politicians or private sector industrialists. In short they mainly just continued to be the ones in power, being largeley sacrosanct from attacks about their political past and current successes. During the 1960s the first voices of dissent came from students, garnered public support from the repercussions of the Auschwitz trials. Throughout the time of her existence the GDR tried to inform the world about this often unbroken continuity in personal, politics and attitudes. By far not all of that was mere socialist propaganda. The elites kept largely their places, influence and attitudes.

A really tiny minority was prosecuted, even shamed publicly. But the vast majority of die-hard nazis just kept on naziing, now under 'democracy': Globke, Kiesinger, Schleyer, Filbinger, Beisheim are just some of the world-known examples.

When in 1994, after decades of negotiations, the USA returned documents from the Berlin Documentation Center (BCD) to the Federal Republic of Germany, the public gained the impression that the Federal Republic had been governed in its early years by former NSDAP members. The NSDAP membership card index kept in the BCD revealed familiar names: three Federal Presidents — Karl Carstens (CDU), Heinrich Lübke (CDU, Walter Scheel (FDP, previously Foreign Minister), former President of the German Bundestag, Richard Stücklen (CSU), Foreign Minister Hans-Dietrich Genscher (FDP), Economics and Finance Ministers Karl Schiller (SPD) and Liselotte Funcke (SPD), head of the Chancellery Horst Ehmke (SPD), former leader of the CDU/CSU parliamentary group, Alfred Dregger, and many others more.

The impression was not misleading. In Willy Brandt's government alone, twelve former National Socialists sat at the cabinet table.

— Katja Tichomirowa: "Nazi-Vergangenheit von Politikern Ein doppeltes Spiel", Berliner Zeitung, 21.06.2013.

This Liste ehemaliger NSDAP-Mitglieder, die nach Mai 1945 politisch tätig waren is horrible – but mainly for its incompleteness.

Support for wars, nationalism, antisemitism, political hatred directed at groups like xenophobia, h*m*phobia, plain racism etc are quite stable over the course of the years since 1945 at 10% of the population for the openly extreme forms and 50–60% for the more disguised forms like secondary antisemitism. The support for most actual political content of nazi policies is still at the same level as of 2018.

— Hermann Kurthen, Werner Bergmann, and Rainer Erb: "Antisemitism and xenophobia in Germany after unification", Oxford University Press: Oxford, New York, 1997. // + Antisemitismus in der deutschen Bevölkerung, SZ, 2018, Die Feindseligkeit wächst weiter, Wie antisemitisch ist Deutschland?, FAZ, 2018.

Update for the updated question:

It might be misleading to focus just on 'voters', after the war. After all the NSDAP never had a majority vote to begin with when the conservative elites instructed them to take power. The more interesting angle is found indeed in the coping strategies of the 'ordinary' executioners of Hitler's will.

The sources already mentioned include some doubts, regret and misgivings over time and the course of the war. The focus of most material is on the personal hardships, or stupid military leaders. The latter curiously often present Hitler as not being part of that ledaership. In parallel to "who'd have known in 33 what came to pass" there was "if only the Führer knew!" (he'd rectify the situation).

In another example, a POW regretted that the constant manipulation of Hitler unjustly diminished his historical significance. But even more lamentable was the fact that the misinformation of the Führer had led to things for which the German military was now going to be held responsible. Major General Reiter articulated this fear:

REITER: He was a historical figure; only history will be able to give him his proper due; one must first hear all that happened; we have heard nothing. Those incompetent fools who never told the FÜHRER that he was being lied to in reports etc! We, too, shall be blamed for that, you can be sure of that.

— SRGG 1176 (C), 2 May 1945, TNA, WO 208/4169. Quoted from Sönke Neitzel: "Soldaten: Protokolle vom Kämpfen, Töten und Sterben." Knopf: New York, 2012.

The post-fascist Germans encapsulated their soul in strange constructions:

In return, the German population frowned and said: you spoke throughout this war of freedom, but now you impose on us only restriction and deliberate suffering. What do you want with us seventy million? Only to make us suffer more than we already do? Yes, the war was bad. However, we are not just the people of Hitler and Himmler, but also of Beethoven and Goethe. We have lived here in the heart of Europe for hundreds of years, mostly no less peaceably than our neighbours. We shall carry on living – unless you want to kill us all. So, again, what do you want with us?

— Frederick Taylor: "Exorcising Hitler. The Occupation and Denazification of Germany", Bloomsbury: London, 2011.

Surely, everyone notices that in this version of events something is amiss.

Just like in Austria, the Germans resorted to painting themselves as not only the vanquished but even as the victims. Strangely removed from a few years prior, cause and effect have lost meaning to a degree and the collective delusion was Niederlage/Zusammenbruch/Stunde null (defeat, total collapse, zero-hour), forgetting and looking forward. This epitomised in the expression of 'the persecuting innocence' (die verfolgende Unschuld).. It took until 1985 that a head of state (who fought on the Eastern front in the war of extermination, no less) even could use the phrase "May, 8th was also a day of liberation for us Germans", and was met with applause but also considerable opposition. (Take note that this is now the default position for 'official Germany'.)

For example the works of Harald Welzer like "Opa war kein Nazi" ("Grampa was no Nazi" 2002) show that this is still by far not the majority position in private family memories.

For quite an intimate account, albeit very much on the side of unreliability for most of its content pertaining to the subject matter, Hitler's secretary allows quite the insight into the psychology of a very ordinary German.

According to Traudl Junge, she never felt sorry for herself, even in the chaotic hours and days of the collapse of the Third Reich. "That would be even better," the reader may think. However, it does not only distinguish them from many of their closest colleagues at that time, but from the broad mass of contemporaries who subsequently stylized themselves into "victims". "These were difficult times…" — "It was just war…" — These were phrases that made it easier for many after 1945 to suppress or at least trivialize the facts of the persecution of the Jews, the extermination camps and other National Socialist atrocities. They had experienced the "total war" and its material and ideational destruction as a "total collapse" and had set themselves up against the fiction of a "zero hour". They spoke of the "eliminated spook" and the "broken spell". They tied their hopes to the new epoch "after the war", perpetrators as well as persecuted, passive followers or vicarious agents, as Traudl Junge was one.

She never felt innocent after the war. As torturously present as her shame and grief over the Nazi disgraceful deeds are, it has been difficult for her to locate her co-responsibility beyond a diffuse, abstract self-accusation. Her personal failure, if she finally finds out, lies in having called on Albert Bormann's help. She wanted to go to Berlin in 1941 and was furious and stubborn about the difficulties her Munich employer had put in her way. In order to achieve her goal — Berlin, not the Reich Chancellery or even Adolf Hitler — she silenced the warning voice that had spoken to her: "Don't get involved with the party — that can't go well." When she finally stood before Hitler after a series of coincidences, it was too late to resist, she says. Today she knows that she was blinded by him — not by his ideological and political intentions, which never interested her much, but by Hitler as a human being. She does not belittle the fact that she served him as a lady of society, while he and his helpers pursued the "final solution". She admits that she probably only knew half nothing about the extent of the persecution of the Jews because she did not want to know.

— Traudl Junge: "Bis zur letzten Stunde. Hitlers Sekretärin erzählt ihr Leben. Unter Mitarbeit von Melissa Müller", RM Buch und Medien: München, 2002.