The first critical tests to confront the Republican presidential hopefuls in January will come in Iowa and New Hampshire, but campaign officials and their candidates will also be keeping a close eye on the “invisible primary” as year-end fundraising results start to trickle in.

Although campaigns have until Jan. 20 — the day before the South Carolina primary – to report their donations for the last three months of 2011, candidates with impressive hauls are sure to make their figures known far earlier through well-choreographed leaks, designed to add a boost of momentum at just the right time. When they choose to release their figures could say as much about the state of their campaigns as the figures themselves.

For a few candidates, that moment has already come. Various reports citing unnamed sources in Mitt Romney’s campaign have predicted a fourth-quarter haul of around $15 million to $20 million. 

“We’ll do better this quarter than any other quarter so far,” Romney told reporters on Sunday.

Newt Gingrich’s campaign, struggling to fend off the impression that his support is plunging in Iowa just days before its first-in-the-nation caucuses, told reporters on Wednesday that he would report about $9 million — far exceeding what he raised in all previous quarters combined.

For every candidate except Romney, the final three months before the Iowa caucuses were erratic and unpredictable, as Rick Perry, Herman Cain and Gingrich each took a turn at the top of the polls. That volatility has made it difficult to predict the size of each campaign’s wallet.

But if money follows momentum — and it usually does — each of those candidates will have seen a temporary spike in donations during their moment in the sun. The question will be whether they capitalized on their newfound success quickly and effectively enough to yield a solid number for the entire quarter.

“Romney has stayed steady, except for one little hiccup in December,” said one Republican strategist. “Perry started great, but ended not so formidable. [Michele] Bachmann’s trajectory has pretty much started and finished at the same place.”

Rick Santorum almost certainly had an uptick in fundraising in the final weeks of the year, the strategist predicted. Ron Paul made gains on his previous fundraising performance, but ended the quarter on the defensive.

The last time campaigns opened their checkbooks to the public, at the end of September, Perry and Romney were the big dollar winners. Buoyed by a splash entrance to the race in August, Perry raked in $17 million in less than eight weeks. Romney raised $14 million between July and September, while no other GOP candidate broke the $5 million mark.

The eventual nominee's opponent, President Obama, a consummate fundraiser with an unchallenged campaign structure, hauled in $70 million for his reelection and the Democratic Party during the third quarter.

To concoct an early prediction of fourth-quarter results, General Sentiment, a research firm that tracks social media, divided each candidates’ third-quarter hauls by the number of positive mentions they received that quarter on Twitter, Facebook and other sites. That ratio was then applied to the number of positive mentions each received in the fourth quarter to project how much they raised.

According to the firm’s analysis, which was obtained by The Hill, Romney should come out on top in the fourth quarter with an estimated $31 million. Paul comes in second with $13.4 million, with Perry close behind at $12.7 million. Gingrich comes in fourth with $5.8 million, while Jon Huntsman, Michele BachmannMichele Marie BachmannBachmann won't run for Franken's Senate seat because she did not hear a 'call from God' Billboard from ‘God’ tells Michele Bachmann not to run for Senate Pawlenty opts out of Senate run in Minnesota MORE and Santorum all fall at $2 million or less.

“Social media numbers are probably most accurate for a candidate like Ron Paul, who attracts lots of donors with small amounts — especially through his money bombs, which are all driven by social media,” said Steve Kwon, a research analyst for General Sentiment.

As the real numbers start to trickle out, candidates will be eyeing each other attentively for signs not only of support and momentum, but of the resources necessary to wage what could be a protracted and costly presidential primary. More than in previous quarters, cash on hand and debt levels will be scrutinized for evidence as to whether candidates have the means to survive the long haul.

Barack ObamaBarack Hussein ObamaRivals and consumers will rein in Facebook, not regulation Obamas send handwritten note to Parkland students: 'We will be there for you' Water has experienced a decade of bipartisan success MORE's campaign and my Republican opponents will use the numbers we report not only as a sign of our campaign's strength, but also a sign of the strength of our conservative values,” read a fundraising appeal from Bachmann on the second-to-last day of 2011. “You may not be able to cast your vote in an early caucus or primary state, but you can make your voice heard today.”

Unlike four years ago, campaign coffers won’t be the only part of the story. Political action committees (PACs) and super-PACs are bearing an increasing share of the task of funding the air wars, particularly the negative attack ads that have been central to Gingrich’s recent demise in Iowa.

Those groups, freed from some campaign finance regulations by the 2010 Citizens United Supreme Court decision, have more lenient reporting requirements and the ability to accept larger sums than campaigns can accept. But they could also leave a bad taste in the mouths of voters, who are reluctant to support candidates they deem to be bankrolled by special interests.

“The Republicans have a decision to make,” said Michael Fraioli, a strategist who raises funds for Democrats' candidates. “Unless something changes dramatically, the Obama for President campaign is going to raise the money it raised last time from individual donors. They don’t take PAC money. They don’t take lobbyist money.”

And for Obama and Democrats up and down the ballot, nothing could be better for their own fundraising prospects than the sideshow in Iowa and New Hampshire, where candidates are outdoing themselves trying to charm the most conservative elements of the GOP base.

“Imagine the amount of Advil that [House Speaker John] BoehnerJohn Andrew Boehner4 reasons Mike Pompeo will succeed at Foggy Bottom The misunderstood reason Congress can’t get its job done GOP sees McCarthy moving up — if GOP loses the House MORE [(R-Ohio)] and [Senate Minority Leader Mitch] McConnell [(R-Ky.)] are taking,” Fraioli said. “These folks are probably praying for Iowa to be over with — it can’t be over fast enough for them.”