Today the presidential campaign will be largely defined by the testimony of Iraq commander David Petraeus. Is it just me or is his typical gravitas undermined by the sight of (the talented!) Dana Milbank just over his right shoulder as he testifies?

More on Petraeus politics as the day unfolds. McCain just gave a standard we-cannot-fail opening spiel. Hillary speaks soon and Obama questions him midafternoon.

--Michael Crowley