They need to ask themselves whether they really want to be responsible for electing Hillary — because that will be the result if they don’t get their act together, smell the coffee and start supporting Trump.
Instead if trying the age old, often used, and rarely successful meme of “not the other guy”. Try getting people to vote FOR your candidate instead of against the other guy.
Trump is not my guy, the GOP is not my party. I will vote for my part’s candidate, you vote for yours. If you want me to change my vote, then offer a reason to reconsider why I have already rejected your candidate.