David Brooks explains McCain's next big challenges in a piece today:
John McCain is exhausted. He hasn’t had a full-night’s sleep in forever. It took him 10 hours to get to California because of flight trouble. He underperformed in the debate Wednesday night, as his staff understands. He took some shots at Mitt Romney that were gratuitous considering the circumstances, as he privately acknowledges.
But somehow in the midst of all this frenzy, McCain has to transition from being an underdog to being a front-runner. He has to transition from being an insurgent to being the leader of a broad center-right coalition. He has to transition from being a primary season scrambler to offering a broader vision of how to unify the country.