"There are very few Americans -- and frankly, probably very few people worldwide at this point -- who don't have a pretty crystallized attitude about Donald Trump. I don't think he can appeal to uncertain voters," Klar said. "At this point, his best strategy is to garner as much enthusiasm among the people that already like him."
All of the enthusiasm in the world doesn't matter if you are only 28% of the electorate.
No, but it can affect state/local policies for voting. When I lived in NC in a majority-black area, I had to wait in line for literally hours to vote. A lot of people can't afford to wait that long, or can't physically do it. In Illinois? Tons of early voting options and lines are usually really short with little to no wait.