So I think this is reasonable as well, but I think you and I were always very likely Democratic voters.
I think that there's a meaningful segment of consistent GOP voters who are really on the line on Trump. They hate Hillary because they've been trained to hate Hillary, but they don't think of THEMSELVES as racist, so it's hard for them to justify voting for an aggressive racist.
If they're quietly racist, it's probably justifiable. Even with Trump saying he wants to build a wall and keep out Mexicans, well, if that's the worst thing he says, maybe he's just really strong on immigration, I dunno. But every time he says another racist thing he's threatening their ability to turn out for Donald Trump and still feel like they're good people. So Trump is actively losing these people with every statement he makes. (And the fact that the GOP politicians are condemning their own nominee's rhetoric is going to hurt even more.)
I think there's another similar group on the other side -- unlikely Democratic voters. America's filled with unlikely or unregistered voters who would vote Democratic but can't afford the time and energy to get registered and then actually go get vote, or don't see much reason to bother to do so. A lot of those people are people of color, who naturally have less faith in our government in general.
Trump gives those people a very real reason to turn out. You're probably going to hear about Donald Trump no matter how disengaged you are, and you're going to hear just how terrible he is. Every one of these statements activates another bunch of Latinos who could be voters but just haven't felt motivated enough up til now.