I live in New York where Republican candidates for lesser offices don't always exist. Seriously, my Congressman (Nadler) polls between 85 and 90% every election.
More importantly, have you contacted this GOP candidate's office and expressed your concern that Focus on the Family Action is besmirching his/her reputation by including the candidate's name in one of their mailings?
Take the high road (at least at first) and say that you feel it will detract from the candidate's credibility if this association is not refused immediately as it must have been some mistake. See what happens.
Have fun with it. It is all you can do at this point.
Where are you?
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher