This is a fine kettle of fish. I blame the Tea Party.
Ted Cruz wasn’t acceptable either, although for different reasons than Trump.
I don’t want Hilary Clinton or Bernie Sanders nominating Supreme Court justices — even more so if, as seems quite possible, the Trump candidacy at the top of the ticket causes Republican candidates for Senate to lose in numbers sufficient to give the Democrats the majority in that chamber.
The silver lining is that when Trump goes down to crushing defeat, Paul Ryan will be the top Republican in D.C., and the Tea Partiers should realize that their intransigence doesn’t work.
My dilemma is whether I should vote for a third party candidate (effectively helping the Democratic candidate), or vote for an unacceptable major party candidate. Fortunately (?) my decision is inconsequential, since the Democrats are sure to carry Massachusetts anyway. Cf. http://www.constitutionparty.com