If your answer is "well, I guess we have no choice but to align with the folks that think Jews are a pestilence to be eliminated and the cause of all our issues," you can get all the way fucked. Fuck the monster who pushed it, and fuck the weaklings who joined along.
If we need to stand for counter arguments that back that, we're too weak to stand for much.
That wasn't what they *THOUGHT* they were agreeing to.
First, they were stuck between allying with the Communists and allying with the Nazis so there were no good options.
Second, the Communists were a bit more insistent in their anti-democratic refusal to join with others. Ie, the Communists more-or-less demanded total control whereas the Nazis agreed in principle to a coalition government.
In theory the Nazis didn't have much control in the initial Hitler Cabinet. Hindenburg (elderly WWI war hero General) was still President and most definitely NOT a Nazi. Additionally, the Vice Chancellor, Minister of Foreign Affairs, Minister of Finance, Minister of Justice, Minister of War, Minister of Economics, Minister of Agriculture, Minister of Labor, Postmaster, and Minister of Transport were all non-Nazi's. The only Nazi's included were Hitler as Chancellor and the Minister of the Interior. Goebbels and Goring were added soon thereafter to newly created posts.
The people who made the decisions were in a terrible situation with no good options. Judging them with the benefit of hindsight isn't fair to them. At the time they *THOUGHT* that Hindenburg, von Papen (the Vice Chancellor), and the other non-Nazi ministers could keep the Nazis from taking full control or doing anything too crazy. My point isn't that it worked, it obviously didn't. My point is that they were constrained by the lack of viable options and at the time this looked like the best bad option available to them.