HAMPTON, N.H., 11:30 p.m. — When a Yale student stays up all night, it’s usually because they are in a pickle — say, a term paper is due the next day, and they don’t have the requisite number of pages written.

When a presidential candidate, the same can be assumed. While former Senator John Edwards campaigned the night away, Senator Barack Obama slept like a baby. That’s because Obama is the frontrunner — and Edwards, to put it bluntly, is in trouble. But instead of pages, he doesn’t have enough votes.

And the former vice presidential candidate didn’t deny it.

“I am the underdog, there is no doubt about that,” he said. “Nobody expects us to do anything.”

But on Monday, Edwards surpassed expectations. He didn’t fall asleep.

In a speech to 150 supporters here on Monday afternoon, more than 36 hours since he last slept, Edwards did not look a bit tired. To the contrary, he gave a fiery speech, emphasizing the populist platform he has stood by all along. “Change” was not the word of the day. “Fight” was the word.

“We’re going to speak the truth, and we’re going to start with this primary in New Hampshire tomorrow,” Edwards said. “You’re going to say, ‘Enough is enough,’ and you’re going to rise up, and speak out, and you’re going to say, we are going to fight for the promise of this country.”

“And when it’s over,” he said, “every one of you will be able to look your children in the eye and say, we did for you what our parents did for us. We left this country better than we found it, and we made absolutely certain that you would have a better life than we did.”

— Thomas Kaplan