I doubt there are many nudist Republicans in Florida or in the rest of the country. Foley is doing this to score points to conservative voters in next year's primary and to dispel the notion that he is gay, which would turn them off from his candidacy.
Whether he is a homosexual or not may not affect his candidacy. I'd think that if he is homosexual that could get him some support in South Florida (but he could get a backlash statewide). The question is if the crossover votes he gets would outweigh those who would stay home or leave the office blank (I doubt that conservatives would cross party lines for his lib opponent).
The primary is where they will have their say.
I don't know Florida politics enough to know how his pro-abortion stance will affect his candidacy (but I would suspect that it's a bigger factor than if he is a homosexual).