If there's one thing that the voting public loves, it's a good comeback story. At one point, just over a decade ago, Mel Gibson looked like he was down and out. He was having a very public struggle with alcoholism, he'd been recorded making some deeply unsavory comments about Jewish people, and it seemed likely that his Hollywood career was over. It wasn't. Gibson got help, got sober, and came back as both a performer and a director.
Sometimes, it's better to have fallen and gotten back up than never to have fallen at all. It shows people that you're resilient, and you can deal with tough times. It also makes you relatable - very few of us have led blameless lives, and so we can all identify with those who have made mistakes and sought forgiveness for it. Gibson could campaign on that kind of platform - and he'd probably seek tighter controls over celebrity gossip in newspapers too.