I would surmise that it's not that they don't care, it's that it won't affect them personally so then they don't need to care. We're intensely myopic creatures. Things aren't a problem unless they're a problem for us. So sure, Trump will deport migrants. That won't affect them...until they want to fix up their house or the price of agriculture or meat goes up tremendously. It won't affect them until a family they knew is suddenly gone with no explanation. They don't care about abortion restrictions because they don't plan on having one. Then their daughter wants to have a baby and there's a problem where she's going to die unless the baby is aborted or is a risk to the mother and is beyond saving.
We are a society that has an extreme lack of empathy. We want ours and we don't care if others get them. We also don't want to be inconvenienced by anyone else. We're happy thinking someone else will take care of the problems out there. That's why we gravitate to strong men who are tough on "others". It's a tale as old as our country.
And I agree, if you were undecided, you're either not voting or you're voting for Trump. There's simply no other way that you can overlook who he says, what he's done, and what he says he's going to do if he gets elected again. It says more about us as a nation that this isn't already a massive blowout. He's literally everything he claimed about Biden. The differences between them grow starker and starker every day.