One measure of enthusiasm among a party’s base heading into an election year is early fundraising returns. In the second quarter of 2007 leading Democrats hauled in major campaign cash, an early sign of the enthusiasm gap that they would enjoy throughout the 2008 election cycle. And when Barack Obama outraised Hillary Clinton, $32.5 million to $27 million for that quarter, it demonstrated that Obama would be able to mount a serious challenge to the frontrunner.

This time Republicans, as the party out of power and fueled by an angry electorate, are supposed to be the beneficiaries of the enthusiasm gap. The stronger turnout among their base in the 2010 midterms was a major reason for their victory. And so the remarkably weak fundraising numbers among Republican presidential candidates for the second quarter of 2011 may be a bad sign for the party as a whole.

Among the candidates who have released their numbers so far—Rick Santorum, Representative Michele Bachmann (R-MN) and President Obama have not—Mitt Romney is the clear leader. The former Massachusetts governor raised $18.25 million dollars, all of it for the primaries. (Sometimes a frontrunner will get donations from donors who have already given the maximum for the primaries and will hold that in reserve for the general election.) His next closest contender? Representative Ron Paul of Texas, with $4.5 million. Since Paul is too eccentric to win the nomination, that means none of the plausible alternatives to Romney have mustered the financial might to challenge him. Former Minnesota Governor Tim Pawlenty has raised $4.2 million, but that number does not break out how much might be general election funds that he cannot currently use and whether there are debts or delayed payments he must meet. Reportedly, some of Pawlenty’s top aides have been working without pay.

Former Ambassador to China Jon Huntsman took in $4.1 million, but that includes money he donated to his campaign from his own personal fortune, after saying that he would not self-fund. (Huntsman joined the race only towards the end of the second quarter.) Former House Speaker Newt Gingrich’s campaign continues to falter, with only $2 million raised this quarter and, according to some news accounts, only $225,000 cash on hand $1 million in campaign debt.

Even Romney’s returns could be considered underwhelming. In addition to lagging far behind the money that Obama and Clinton brought in four years ago, they lag his own stated goals. This spring—as rival campaigns are eager to point out—Romney was hoping to raise $50 million by early summer, a mark he has missed by a wide mile. But they are not shy about doubling down on that goal. “We are extremely proud of the strong support Mitt has received across the country. We intend to raise $50 million and more for the primary campaign and we’re off to a very good start,” said Andrea Saul, spokesperson for the Romney campaign.

One possible explanation for the unimpressive returns is the Citizens United Supreme Court decision, which opened the floodgates to unlimited fundraising by outside groups. Republican donors who want to help the cause generally without picking a specific candidate too soon now have plenty of other places to park their money. Karl Rove’s Crossroads GPS is already spending $20 million dollars on ads attacking President Obama. Of course, attacking President Obama is something all Republicans can agree on. Eventually they need a candidate to be for, not just a president to be against. So far, it seems, they remain underwhelmed by all their choices.