As I said to a friend late March, after the Rubio campaign cratered, it was hard for me to maintain interest in the race. At that point it would probably come down to choosing the best way to lose. Like being offered a choice of how to be executed: would you prefer death by hanging or firing squad?
Well, here we are!
The best argument for supporting Trump is the devil you know v. the devil you don't. Hillary is the devil you know. Trump might be as bad. Hard to see how he could be worse. He might be better.
However, one problem with that argument is that it's too atomized. Even if Trump considered in isolation is better than Hillary (debatable in itself), a President is the titular head of the party, and face of the party. If that's Trump, it will drag down the whole GOP. Discredit the Republican brand.
Mind you, there are people who support Trump precisely because they wish to destroy the GOP. However, Trump may damage the GOP either way. If he loses to Hillary, which is likely, his loss may well have a chain reaction on downticket races. That means, not only will Hillary be elected, but the opposition party will be swept out of power. There will be nothing left to block the liberal agenda.
Speaking for myself, I've already indicated that I find voting for Trump too self-degrading. I will let the chips fall where they may.