@freemo Many people can't see past the next election. Voting for a third-party candidate may "waste a vote" today, but it may be the difference between, for example, whether or not the party has ballot access four years from now.
to vote for a clearly evil candidate just because you want to wind up on the same side of the majority sounds wrong on every level and the root of most evils in a sense (doing something you know to be wrong simply to fit in with the crowd).
There is certainly no factual argument to show why you would do more good voting a primary party.