It's unclear how much the shortfall will matter. For one thing, a so-called Super PAC run by several of Romney's advisors will spend many additional millions on his behalf.
Also, most close observers believe that Romney will spend whatever is needed from his own fortune, estimated at roughly $250 million. (Some of his former associates suspect the figure is much higher.) That's what Romney did in 2008, when he put nearly $50 million into the campaign.
In fact, that expectation may be one of the problems. In early 2007, many donors might have believed Romney's insistence that he didn't intend to fund his own campaign. Those claims sound less plausible now.
"It's the rich-guy candidate hazard," says Gray. " 'If he had $47 million to spend last time around, he doesn't need my $2000.' "
Romney was able to generate urgency and enthusiasm among potential donors in early 2007, less from a sense that the campaign needed the money, than from the desire to use blockbuster fundraising to vault Romney from the pack of unknowns into the top tier. Back then, in conference calls with campaign staff and fundraising volunteers, the first quarterly report of campaign finances was referred to as "the first primary."
This year's disappointing fundraising tallies have prevented Romney from establishing an aura of dominance and invincibility — which in turn has made it easier for potential donors to wait and see. "It's extraordinary how little bandwagon effect there is for him," says one longtime Massachusetts Republican insider.
There is no single explanation for the desertion of more than 10,000 individuals — a potential loss of some $25 million to the campaign.
But one conclusion is inescapable: even among his supporters, there's not much enthusiasm for a Romney presidency.
And that, according to his supporters and detractors alike, stems from Romney's ever-changing persona. Whatever version of Romney you once supported, it's not the same Romney who is asking for your money today.
The desertions include not just rank-and-file givers, but dozens and dozens of "bundlers" (supporters who both donate their money to a campaign and solicit funds from others) who helped raise money for Romney's 2008 effort.
The loss of bundlers is perhaps most stark — and potentially troubling for the campaign — in Florida. That state is critical to Romney's nomination and to his fundraising strategies.
Romney's 2008 Florida Finance Committee, announced in February 2007, was a powerhouse of 77 in-state fundraisers. Only 13 of the names on that list are on Romney's Florida Finance Committee for his 2012 run — a stunning attrition rate of 83 percent.
Romney's fundraising depends heavily on bundlers like those. Roughly two-thirds of the money he raises comes from donors who give the maximum allowed, and in many cases it's easy to see the wealthy networks they funnel through.
A prime example is Carl Lindner Jr., the 92-year-old multi-billionaire head of American Financial Group who died last month.
Lindner, one of the nation's top conservative givers, had no direct history with Romney, but joined his fundraising team at the start of 2007. Through Lindner and his family, Romney received high-dollar donations from hundreds of individuals in Ohio, most living or working in Lindner's home of Cincinnati.