My only thinking here is what did the Dems expect to happen?

Expectations: A guy they've worked with over the last decade-and-change, seems reasonable when compared to the rest of the bootlicks/apparatchiks/suckfish that surround Trump.

Reality: Do they not remember when he was coerced into voting against his own (fairly well crafted, if I remember correctly) immigration bill?

I understand why the Dems think this way - democratic norms, etc. (looking at you, Schumer). But, man, how many times does the scorpion have to sting the frog?