From what I understand, the cultural attitude towards Jews in Germany was largely negative even before Hitler was in power. What was the reasoning behind this? What details are there about the average German's feelings about Jews in the time preceding the Holocaust?
I want to just say ahead of my comment here, that my post is written to clarify a point and then make you ask more questions, because this is a very touchy and difficult question to answer.
It is important first to understand the complexities of antisemitism in Europe and thus in Germany. If we take the lands that are Germany today, then the oldest Jewish community goes as far back at the 3rd century CE and antisemitism as a mass phenomenon begins about 1095 when Pope Uran II called for the Crusades (though it has earlier roots as well). Mass pogroms across Europe would subsequently take place against Jews over the next 10 centuries.
With this in mind, let's take some topical factors into account: By the 1930s Germany as a state was only 60* years old; Germany was a mass of different political ideas, of proletariet and middle-class workers as well as a land of centuries old intellectual traditions; Germany was a place of regional traditions, dialects, and with a larger German culture and language as well; and important too Germany was a land of odd contrasts: a strong socialist tradition and a strong militaristic tradition. I could go on, but we need to take as much as possible into account, when speaking on the history of nations/nation-states.
Saying "the Germans" is difficult to qualify.
Do you mean the German in the Ruhr, who fought in WWI, joined the Reichsbanner Schwarz-Rot-Gold (a massive socialist-pacifist organization post-WWI), now worried for his childrens' well-being in another economic downturn? Do you mean the German, who has lived on a farm his entire life and is a member of the Communist party, who fought in the uprisings in Saxony? Do you mean the German student in Göttingen studying law, who isn't politically active?
Like anything, generalizations are a hard sell, but there is something all three of those (I only chose men! woops) German men have in common: all of them had never once in their life met a "Jew" and if they did, they had no idea they were speaking to one. By 1933 there were roughly 535,000 Jews living in Germany. Of those roughly 80% were German-Jews and roughly 20% were Jews who had immigrated from the East, many of which had moved to Berlin. In regards to the former, these were first and foremost average Germans: they spoke German, not yiddish, and most did not understand Hebrew, or get a Bat or Bar Mitvah. For most German Jews, their Judaism was not their identifying feature, nor would there have been anything to identify them as Jewish by a non-Jewish German. We are speaking in general terms again, but Jews of Germany were not like the so-called Ostjuden.
So the Holocaust (if we accept the terminology) was the brainchild of an ideology that came from a country where the Jewish population was 0,77% of the total population and most of those were Reform Jews, unable to be identified as Jews at all? o_O
Add to this that one of the centers of the Haskalah (the "Jewish Enlightenment" a reactionary movement to The Englightenment) was in Berlin in the 18th century, headed by a man called Moses Mendelssohn, AKA the German Socrates, and you should be scratching your head and rewording question "why did the German population dislike Jews enough to go along with having them systematically removed from society?"
At this point it is also really important to stress that obviously there were Germans, who had varying degrees of Antisemitism: some may have had stereotypes of money in mind, some may have had stereotypes of socialism and marxism in mind, and some (the Nazis for example) saw "the Jews" as involved in a larger conspiracy against the German people beginning with the November Revolution, followed by the Weimar Republic, "bolshevist" uprisings across the country, and the signing of the Treaty of Versailles. Unfortunately the larger fear of bolshevism which had been spreading across Europe had mended itself in the minds of many across the world with the Jews; this meant Bolshevism and "the Jews" became interchangable in some circles.
Returning to Gemany though, Communism/Bolshevism was considered by many as a legitmate threat, but as for the German-Jews, this was just never something Germans saw. Perhaps this is why when the Nazis came to power, regardless of the small population of Jews in Germany, they did not outright attack them. Instead they wanted to build up a natural pogrom, allowing the German people to purge the German-Jews themselves, but this never happened and instead their rights were progressively stripped away to a point much further than the average "Aryan" German's was, to allow persecution and exploitation.
Since "the Jews" were never a real threat the most vulnerable and dangerous to the regime of the NSDAP were rounded up first: SPD, KPD, later homosexuals, Roma, "work-shy" etc. while German-Jews (mostly middle-class) were to be made second-class citizens and pressured to leave the country. They did. Over half of all German-Jews were gone by 1938 when Kristallnacht had taken place and those, who could afford to leave after that, did. Unfortunately, there were those who stayed or could not leave. Around 160,000 German-Jews were killed in the Holocaust.
So why did "Germans go along with Jews being systematically removed from society"?: During the 1930s it was clear to the any "Aryan" German, that German-Jews had become second-class citizens, but it was a slow and progressive event. If German-Jews were leaving they were proactive in doing so themselves. After 1938, when the state used violence against the German-Jews, the Reich showed its willingness to use violence as a tool in public. So the question was, how brave would you be to protect that old neighbor, colleague, or friend, who was Jewish, when you and you family would be then put in his or her place after the Gestapp or SA found out? After 1941 if you lived near a concentration camp (and depending on if you could see those who were getting off the trains marched off) you knew something bad was happening, but there was little to be done. Even paying too much attention could mean you be put there yourself or simply shot. But ultimately it came to this: you either agreed with what was happening (I think a minority of the once civilized nation) or were at the point of self-preservation for you and your family. Also, important to add, if you lived in, lets say, Weimar and saw prisoners marching off to Buchenwald, most were not Jewish, as was the case for most concentration camps in Germany. This perhaps would give some perspective to those brave enough to stare or loiter around those places that it was not only the Jews going to these strange work camps, but Poles, Russians, and POWs from all nations.
Returning to the topic though, what is also remarkable is that the Nazis themselves saw German-Jews diffirently and their nonsensical ideology had a variety of holes. Roughly 8,000 German-Jews were still in Berlin in 1945 (many of these were in hiding though) and this has much to do with unsettled questions of German-Jews married to Aryans, German-Jews who had served in the armed forces in WWI, and German-Jews working in factories for the "war effort". Otto Weidt, a small semi-blind factory owner in Berlin, managed to save 27 Berlin-Jews using this exception along with bribery and also helped to hide some of his employees.
Hopefully you have noticed that I only spoke of German-Jews in this post. The unique treatment of German-Jews before Operation Barbarossa, never existed for Polish-Jews, Russian-Jews, Hungarian-Jews, and so on. For these people the full wrath of a murderous ideology was brought upon them. I won't discuss the antisemitism of those participants in the Final Solution, since your question was only in regards to Jews within Germany, but note that these were "Germans" just like many others who did not participate in this horrendous stain in human history were "Germans."
I hope this helped a bit!
Edit: A lot of stuff... Edit: More edits