I wonder what's the difference between the "Maybe/It depends" people and the Undecideds.
I am very unsurprised that the number of Yes fell so much, of course.
I think the only thing we can discern from this is that 50-60% of Republicans make up what we can call the Trump Cult, whereas the other 30% (Maybes and Undecideds) are the reluctant Trump voters. All of those maybes and undecideds will vote for Trump if he is the nominee, as will all of the yes people and some of the nos. I think that the nearly 15% of Republicans saying that they won't vote for him at all are the most interesting, but even that I wouldn't glean much hope from since this poll was conducted one week after the violent insurrection.
