Woman running for President of the U.S. gives up the candidacy because she doesn't want something in her past revealed to the public.

Stitchellen, are you sure she was running for President and not Vice President? I am wondering if this is the movie you are thinking of: The Contender (2000) - IMDb

I think you mean the Contender and it's her nomination for VP that's debated.

I am looking for a movie about a young man who had been bullied during his teenage years, decided to have a sex change to a woman the decided to get revenge with one of his past bullies and had sex with him