Which one?
Romney never did.
Thompson may not have either, we don’t know — we just know he was divorced.
Hunter didn’t.
Tancredo didn’t.
Huckabee didn’t.
The ones we KNOW that cheated on their wives are Gingrich and Guiliani, and hopefully neither of them will be our nominee. And I guess McCain? Do we know he cheated on his wife, or did he just get a divorce?
Last I heard (probably just a few threads ago), Giuliani was still the GOP frontrunner.