John Kerry was the Democratic front-runner early last year, a bad one, and the status didn’t last long.

Now that he’s back on top, the dominant figure in a two-man race, the Massachusetts senator may be slipping into his old habits — cautious, cold and a creature of Congress. There are the familiar signs of overconfidence, starting with his curt dismissal of rival John Edwards.

“Look, I’m not running just against him,” Kerry snapped at an interviewer last week. Conveniently ignoring the fact that no other Democratic candidate stands a chance against him, Kerry added, “You know there are others in the race. Obviously, he’s one of the leading contenders.

“I take that seriously.”

But some advisers and supporters say Kerry may not be taking Edwards seriously enough. They recognize in the candidate and his campaign a calculated nonchalance toward Edwards that Kerry once held for Howard Dean, the former Vermont governor who stole the front-runner’s mantle from Kerry in mid-2003.

Kerry had refused to debate Edwards, except for a long-planned forum in Los Angeles on Thursday with two long-shot candidates. He agreed Saturday to a second debate, this one in New York two days before a crucial March 2 showdown.

Kerry’s aides insist that Edwards has not earned the right to stand on the stage toe to toe with Kerry; the North Carolina senator has won a single state, they say with contempt, while their candidate has won 15.

When Edwards criticized Kerry in Wisconsin for supporting the 1993 North American Free Trade Agreement, Kerry all but ignored the attack. Stung by Edwards’ surprisingly close second-place finish in the Midwest battleground state, Kerry returned fire in Ohio last week while suggesting that Edwards, a freshman senator, was not ready for prime time.

“He wasn’t in the Senate back then,” the 19-year Senate veteran said, alluding to Edwards’ relative lack of experience. “I don’t know where he registered his vote, but it wasn’t in the Senate.”

Kerry’s aides acknowledge that they waited too long to respond. “We should have set the facts straight. Yes,” said spokeswoman Stephanie Cutter. “Edwards has talked more about NAFTA in the last three weeks than he did in his entire career.”

Kerry has been tired and sick, two traits he wears visibly on his long, thin face. His health has affected his mood, making him a bit snappish and less likely to flash the smile that softened voters in Iowa.

Kerry has also taken several valuable days off from the campaign trail.

Longtime advisers say weariness leads to long-windedness with Kerry. When he is tired, Kerry lapses into the plodding, superfluous language that permeates congressional debates.

Workers do not just impress him, “they have touched my conscience and my heart.” His message does not just resonate, it’s “ringing loud and clear.”

But some Democrats believe that Kerry is taking the right approach, given his formidable standing. With three small-state elections Tuesday, he could roll up his election-year record to 18-2 as the race moves to March 2, when 10 states award 1,151 delegates.

“If I were advising Kerry, I’d say, ‘Don’t make any mistakes. Be careful,'” Democratic strategist Steve Jarding said. “However, I’d work harder to get the message back on your turf, electability and the military stuff.”