Writing for RealClearPolitics Heather Wilhelm argues Chris Christie is wrong, that the election doesn't boil down too "chicken or fish." She hints at the correct answer, but dances around it because she doesn't like her choices this year.
The right answer is that if, as a Republican not in love with Trump, you live in CA or NY, by all means stay home or leave the president part of your ballot blank. Your vote is irrelevant anyway. All of your states electoral college votes will go to Clinton, regardless of your (in)action.
Similarly if, as a Republican not in love with Trump, you live in MS or WY, you can also stay home or leave the president box blank, your state's electoral college votes will go to Trump anyway, whatever you do.
Only in so-called "battleground" or toss-up states does your vote matter, and there a Republican who does anything except vote "Trump" effectively votes for Clinton. Here is where Wilhelm is wrong, where you really have to understand that nobody but Trump or Clinton is realistically "on offer."
If living in a toss-up state you truly see no daylight between Clinton and Trump, between who they will appoint to the Supreme Court, make an appointment with your ophthalmologist. Your macular degeneration is farther along than you thought.