Purely anecdotal, but I'm hearing Trump is advertising heavily on TV during Texas college football games. Looks like the campaign is feeling the need to shore up support from men in Texas, one of the most reliable demographics for a Republican candidate. As we all know, every penny spent in Texas is one less penny available to spend in a swing state. I don't believe Trump is actually going to lose Texas, but I can see the logic in the Trump campaign feeling the need to advertise there. If Trump does manage to lose Texas, is addition to certainly losing the election in a landslide it would mean a humiliation on a historic scale.
I believe that, and some other indicators, suggest Trump's support is softening. I also think that there's a chance this softening of support may accelerate due to Trump's current turn to the hard right. I think his supporters are motivated more by what they oppose than by enthusiasm for Trump himself. If they have to hold their noses to vote for him, I think there are others out there who are likely to simply sit this one out. Right now, I think Trump's ceiling is 47% and his floor is 37%.
Harris closing the gap by double digits in Iowa is also impressive. Seems there were a lot of "Double Haters" in Iowa who didn't want either Trump or Biden, and they now find Harris a less objectionable alternative. If Harris did that 10+ shift by simply not being Biden, then that should make a difference in other states as well.