I know this isn't the right answer, and probably won't be it for me, but this year just makes me want to stop paying attention to politics ever again and just move on.
Nah, I feel you. Back in '96, the first year I could vote for president, I voted for Dole. I think he would've made a fine president even still, and I'm not embarrassed to say that I voted for him. That's why his support of Trump is so baffling to me (although he hates Cruz).
To be honest, I was pretty much a moderate until relatively recently. Even in 2008, even though I very strongly supported Obama, I would've been OK with McCain. That is, until he picked Sarah Palin. That kind of changed everything. Her whole "palling around with terrorists" nonsense really, really, bothered me, and then the whole rise of the Tea Party after that... Well, it pretty much guaranteed that I'm never voting for another Republican, even for dog catcher, ever again.
And this year has just ratcheted that up to an even worse level. Just the most vile, obscene things coming out of the GOP, even when you exclude the stuff by Trump. It makes you cynical, and the hope for a sane, David Frum-type Republican seems so far, far away.