90 years ago, prominent German physicist Albert Einstein, artist Kathe Kollwitz, writer Heinrich Mann, & others appealed for a unity coalition against the Nazi Party in coming elections.
United the other parties could narrowly win. Divided Hitler would win. The opposition didn't unite.
The sole party that broke from the others and sided with the Nazis was the old Monarchist party that called for reinstating a kaiser. They held few seats, but just enough to give the Nazis what they needed.