When the pot calls the kettle black, so to speak, few people pay attention to the accuser who's equally guilty of the crime. But when Donald Trump calls former President Bill Clinton "fair game" for his infidelities, you can bet many political journalists will be listening closely – and likely smiling.

The latest Trump charge gives reporters a legitimate reason to challenge Bill and Hillary Clinton on the stump, as well as Trump himself. The campaign trail gets a new injection of controversy with Trump's statement that he will go after Bill Clinton's sexual past.

Trump is a brand wizard, so why would he invoke Bill Clinton's alleged affairs, knowing he is equally vulnerable to attacks following an affair that ended his own marriage? He has to know attacks on Bill Clinton's sexual history didn't work in the past, so why would it work now, right?

