In today's biggest event that means nothing and changes nothing, Biden said he won't run for president.

His entrance would've meant nothing to the race (he'd be mired with Kucinich-like numbers), and his decision to stay out shakes up nothing.

The real question is whether Clark steps in our stays out. The signs point to "yes" for Clark, but he's got strong family pressures opposing such a run. The kind of pressures that kept Powell from making his own presidential bid.