People who care about what happens in Democratic primaries are going to vote for the Democrat. People who care about what happens in Republican primaries will vote for the Republican. Yes there are some exceptions to that, and I'm sure a few of them will write endless narcissistic essays on why they can't vote for candidate X. And, hey, whatever. A candidate has to assemble a coalition and it's their job to do that. But the idea that politically engaged people are the ones who are the problem is silly. It's the people who tend not to vote, the people who don't pay too much attention. Those are the people you need to reach, not the people writing boring essays about why they aren't going to vote.