I voted 51-75 % simply because he may at some point actually realize that he is POTUS and start brushing up on his pretty rusty skills and learning ( a foreign concept to Trump apparently). But the way he is going it is only a matter of time before he racks up enough reasons for impeachment.
Do you really think Trump and his advisors would have done what they did if they didn't have assurances beforehand from party leadership that they could get away with it?
Yes he's flying by the seat of his pants, and the only advisor who seems to have his ear at the moment is Bannon.
Republicans in Congress are not going to impeach him, period.
I tend to agree with the caveat that I think you'll see a lot of people trying to save their skins if he falls into the low 20's (not exactly implausible)
I don't believe those who voted for Trump would ever turn on him.
That's like saying Joe Arpaio is safe because he keeps on winning. Until he didn't.
The GOP were NOT going to turn on Trump until they got some of their agenda through (SCOTUS, repeal of Obamacare, taxation, loosening of environmental regs, etc.). However, Trump does not seem to realize that he does NOT have absolute power. He has crossed many influential Republicans and, as if that is not enough, seems to be running "rogue" on policies he knows nothing about.
If he does not calm down, yes I do see a possible impeachment in 2018 (if the GOP polls are bad) or in 2019 (if there is a major change in the Senate).