Updated

Republican Mitt Romney began his drive for the presidency in earnest on Monday, gathering his national fundraisers in Boston and having them call their network of friends and colleagues in a push to raise the first of an estimated $100 million this year.

The former Massachusetts governor hoped the glitzy event at the Boston Convention & Exhibition Center will help establish him as a credible challenger for the 2008 Republican nomination.

A four-screen projection TV system hung from the center of a ceiling, displaying pictures that included Romney in the Oval Office and at the presidential lectern.

"You guys today are my hope. I got to be honest with you. What you're doing is going to make all the difference in the world," Romney told the callers.

Romney said he was considering running to create "a new American Dream." He said he feared for the world his grandchildren will inherit, and said the American Dream of a home in the suburbs "just doesn't cut it."

Besides the "National Call Day" event, Romney also sought over the weekend to shore up his support among evangelicals who have been dismayed to learn that he ran as a moderate for the U.S. Senate in 1994, as well as for Massachusetts governor in 2002.

He now is staunchly opposed to gay marriage, and says he supports a state-by-state approach to abortion rights.

"Now, I wasn't always a Ronald Reagan conservative. Neither was Ronald Reagan, by the way. And perhaps some in this room have had the opportunity to listen, learn, and benefit from life's experience — and to grow in wisdom, as I have," Romney said at a conservative gathering in Sea Island, Ga.

"My life experience convinced me that Ronald Reagan was right. I'm a conservative that gets the job done. And you don't just have to take my word for it, you can just look at my record," he added.

While Romney's presidential committee is still labeled "exploratory," he and his staff have made it clear they are in the race to win.

In e-mails sent last week, two of Romney's sons estimated he would need to raise $100 million to be among the "serious contenders" for the nomination. The stated goal on Monday was $1 million — some of which Romney will need just to pay for the event. Many of the callers, however, paid their own travel expenses.