MANCHESTER, N.H. – Sen. Barack Obama sparked an early frenzy Sunday during his initial visit to the nation’s first presidential primary state, but said he still hasn’t decided whether to run and join a field of Democrats that’s expected to include front-runner Sen. Hillary Clinton and several other more experienced political hands.

“This is an office you can’t run for just on the basis of ambition,” Obama told reporters at a news conference between packed events. “You have to feel deep in your gut that you have a vision for the country that is sufficiently important that it needs to be out there.”

History teacher and Democrat Mark Bingham of Alton, N.H., met Obama and said he could rank among presidents named Lincoln and Kennedy. “It’s good to see politics going in another direction,” Bingham told him.

Obama said he thinks the excitement reflects voters’ desire for a new, positive direction in politics but not about him specifically.

“I think to some degree I’ve become a shorthand or a symbol or a stand-in for now of a spirit that the last election in New Hampshire represents,” Obama said. “It’s a spirit that says we are looking for different. We want something new.”

Clinton has not yet begun campaigning in New Hampshire, but several other potential candidates have been making trips for the last year and a half. Among the most frequent visitors is Indiana Sen. Evan Bayh, who filled a small room at a Manchester conference center Friday night but wasn’t near the draw as Obama on his first trip.

Bayh said he wasn’t intimidated by the Obama mania as he talked to voters one-on-one. “I’m doing the things that matter in New Hampshire,” Bayh said.

Obama answered questions about how his young children, his inexperience, his race and even whether his troublesome middle name – “Hussein” – could affect his candidacy.

He said his family is a major concern because his daughters are 8 and 5 years old. He said questions about his inexperience are valid. Obama said Americans are not concerned with middle names, but that all women and minority candidates have to overcome stereotypes so people will judge them on their merits.

His advisers said he would consider his choice after his Christmas trip to his native Hawaii to visit his grandmother.