This isn't a quick question. This question has been posed by many people in the last 60 years.
First, the only active supporters of the Holocaust were members of the SS and prison guards and a few violent anti-Semites.
Very few of the German people actually "supported" the Holocaust. Although they may have guessed what was going on, it wasn't until late in the war that very many people actually knew about it. It was easier and safer to ignore the fact that Jews, gypsies, homosexuals, etc. were disappearing.
Remember, Nazi Germany was a repressive dictatorship in which children were encouraged to report their parents to authorities for even minor disagreements with the government. In addition, Germany, as most other European countries had a long history of anti-Semitism and pogroms against Jews. Even the U.S. had strong anti-Semitic elements that limited Jews from pursuing certain professions and severely restricted their access to private clubs, colleges and univeristies. Our government turned away at least one ship loaded with refugees from the Holocaust.
Here's a statement from a prominent Christian clergyman in Germany: