Romney's fund-raising team also distinguished itself through its strong organization and use of friendly competition as motivation. Romney kicked off his campaign by raising more than $6.5 million at a one-day telethon in January 2007, where he invited supporters from across the country to the Boston Convention and Exhibition Center.

"It looked like he really had a very strong organization put together, and organization is really what is a major thrust behind fund-raising," said Travis Thomas, national finance director of the Bush-Cheney 2004 campaign, who has contributed to McCain but is not affiliated with any campaign this cycle. "If he can bring that to the table, well, that would certainly be beneficial."

Many Romney fund-raisers also said that whether McCain chooses him or not, Romney's work on behalf of the ticket could lay groundwork for a future run.

Frank Vandersloot, an Idaho business executive, had never raised money for a presidential candidate before he traveled to Boston for the January 2007 fund-raiser and brought in $250,000 in a matter of hours. Vandersloot said he planned to follow Romney's lead in helping to raise money for McCain, but said he believed Romney had a future in national politics regardless of whether he is the vice presidential nominee. "I think there will be a sequel to this story," he said.