Hearing that Clinton ate babies, was nearly dead, was going to take away arms, and was going to force me to install a transgender person in my bathroom didn't actually make me vote for Trump. In fact, I'm pretty sure nothing they said could have made me vote for him.
Again, I'm absolutely sure there is selection bias - but I do live in the State that elected LePage, twice. We sent an electoral vote for Trump and one for Clinton. The Trump voters that I know were probably going to vote for Trump, even if he set fire to a nativity scene while cursing baby Jesus.
I wish there were some way to truly quantify how much impact it had.