Another probable contender with the potential to reshuffle the deck, former senator Fred Thompson of Tennessee, has yet to enter the race. On his first visit to New Hampshire in June, more than 500 people showed up to hear his 10-minute speech.

"Several of ((the other candidates)) have support that's an inch thick and a mile wide," said Dan Hughes, a longtime GOP activist from Newcastle who has been helping Thompson explore a campaign in New Hampshire.

Still, Romney has exploited his head start. Entering the Puritan Backroom restaurant in Manchester the other day, his fifth campaign stop on a blazing afternoon, he seemed eager to seize every chance to win friends.

Frank Messana, 52, a Republican from Bedford, held out a pair of baseballs for him to sign.

"Don't you figure I should get full credit for winning the World Series?" Romney joked.

As the candidate moved on, Messana said he was interested in both Romney and Giuliani. Of Romney, he said, "I like him so far."