Mel Gibson's Recent Troubles and Those of Other Celebs -- Drunken Antics, Foul Language, and Double Standards

With the recent reports of Mel Gibson's behavior after being arrested for DUI in California, the double standards Americans have towards certain celebrities and political figures comes to the fore.

Bad behavoir is simply that, does it matter who engages in it?

Also, why is it that a Republican like Mitt Romney gets excoriated when he uses the term "tar baby" to describe the Big Dig (using the term as it was originally used, to describe a sticky situation), but Jesse Jackson can call New York City "HymieTown", and John Lennon gets away with urinating on nuns?