Yeah, @Chris and I talked about this. Some people who aren't willing to admit they'll vote for Trump in public, will feel a lot more comfortable pulling the lever for him behind closed doors or in a private voting booth. They aren't super vocal about it, but they're part of that silent slice of Trump supporters that will still vote for him.
The same with Biden, actually. I think a lot of people are kind of embarrassed to publicly say they're super gung-ho about Biden when in truth, they actually like him a lot. I was sort of in this camp. Among some of my more liberal friends, I felt a little embarrassed saying I liked Biden more than some more progressives like Warren and Sanders. Mainly because I thought he had more crossover appeal. I tempered down my enthusiasm for Biden in public even though privately, I like him a lot.
So, it goes both ways, I think.