Several reporters, photographers, and TV camera crews were crowded into a small conference room Friday afternoon at the Marriott Wardman Park hotel in Washington. Hundreds of people were lined up outside the room, waiting to enter the “Rick Santorum Meet & Greet” which the program of the Conservative Political Action Conference (CPAC) listed as scheduled to begin at 1:30 p.m. The appointed time slipped past and, like the crowd waiting in line, some in the media gang inside the room began to grow impatient at the delayed arrival of the candidate, who had given a well-received speech that morning in the hotel’s main ballroom.

“We’re a long way from Iowa,” I remarked to Santorum spokesman Hogan Gidley, recalling how few reporters had covered the underdog candidate during the long months he spent crisscrossing the Hawkeye State and speaking to small groups of Republican voters. A mere two months earlier, in mid-December, Santorum had been sixth in the Real Clear Politics average of Iowa polls, with less than six percent. He had somehow miraculously surged to a win in Iowa, then endured a month of disappointing finishes in New Hampshire, South Carolina, Florida and Nevada, Now, fresh from triple victories last Tuesday in Colorado, Minnesota, and Missouri, the former Pennsylvania senator was riding a wave of momentum, attracting the kind of crowds (and swarming media coverage) that follow a bona fide presidential contender.

At last, the candidate arrived, eliciting applause and cheers from his waiting supporters. Santorum answered a couple of questions from the press gaggle, then did a brief TV interview with Andrea Tantaros of Fox News, before the crowd outside was led in to get their “grip-and-grin” moments with the candidate. While the candidate shook hands and posed for photographs with the CPAC attendees, I walked over to talk with his campaign’s finance director, Nadine Maenza, who confirmed previous reports that Santorum had been raking in online donations at a pace of $1 million a day since Tuesday’s trifecta. In fact, Maenza said, she had been informed that the campaign had already collected a half-million dollars that morning, so that total donations to Santorum since Tuesday were already more than $3 million.

Such a windfall of campaign cash, like the crowds of supporters and the swarming media coverage, is further evidence of Santorum’s status as the top rival to the Republican presidential field’s longtime frontrunner, former Massachusetts Gov. Mitt Romney. And the sudden tsunami of contributions is another contrast to those long and often discouraging months that Santorum spent wooing voters in Iowa. His entire campaign operation in 2011 collected less than $2.2 million in donations, which was less than the amount he’d gotten in the 72 hours preceding the Friday afternoon “meet and greet” event at CPAC. Of course, Santorum’s funds are still but a fraction of Romney’s massive war chest, but the influx of contributions almost guaranteed that the 2012 GOP campaign’s longtime underdog could keep up the fight through the March 6 “Super Tuesday” primaries and beyond.

Santorum’s second surge, which evoked memories of the frenetic final week before the Jan. 3 Iowa caucuses, gave credibility to his claim to be the “consistent conservative” alternative to Romney. While some pundits dismissed Santorum’s strong showing last week as an inconsequential bump in the road for Romney, it helped Santorum establish at least a temporary ascendancy over Newt Gingrich as the top “Not Mitt” candidate in the Republican race. Santorum has now notched four wins against Romney, while Gingrich has been unable to replicate his lone victory, Jan. 21 in the South Carolina primary. Gingrich’s stumbles in the past three weeks appear to have badly damaged the former House Speaker’s chances. Few could argue with Gingrich’s assertion that Romney won Florida’s Jan. 31 primary mainly on the strength of “money power” that funded an overwhelming torrent of TV attack ads in the Sunshine State, but Gingrich’s subsequent defeats looked a lot more like self-inflicted wounds.

The Gingrich campaign in Nevada was an ill-organized disaster, and he compounded his Feb. 4 defeat there with a petulant performance at a post-caucus press conference. Then came Tuesday’s embarrassing wipeout. Gingrich hadn’t even qualified for the ballot in Missouri, where Santorum scored a solid 55 to 25 percent win over Romney. Gingrich finished a weak third (13 percent) in the Colorado caucuses, where Santorum beat Romney 40 to 35 percent, and Gingrich placed a distant fourth (11 percent) in Minnesota, where Santorum got 45 percent to Romney’s 27 percent and Texas Rep. Ron Paul’s 17 percent. This string of February drubbings suggested an astonishingly swift meltdown for Gingrich, who in January had repeatedly claimed that he was the only Republican candidate capable of beating Romney, while occasionally suggesting that Santorum should quit the race. After Gingrich’s recent three-week losing streak, it is unlikely Newt will be repeating those claims and suggestions again anytime soon. Indeed, several reports in the past week indicate that the Gingrich campaign is now facing a serious financial crunch, with Las Vegas casino mogul Sheldon Adelson reportedly ending his contributions to a pro-Gingrich “super PAC.”

The bad news for Newt continued at the three-day conservative conference in Washington, where CPAC attendees gave Gingrich just 15 percent of the vote in Saturday’s straw poll. The media made much of Romney’s victory in the CPAC straw poll — 38 percent to Santorum’s 31 percent — but the fact that Santorum beat Gingrich by more than a 2-to-1 margin was arguably more significant. And while there was some sarcastic scoffing when Santorum first accused Romney of having “rigged” a victory Saturday, reports by the New York Times and Politico‘s Jonathan Martin confirmed that Santorum was factually correct: The Romney campaign paid for CPAC registrations and bused in supporters to ensure a win in the closely watched straw poll. Romney’s win in Saturday’s Maine caucus was untainted by any such suggestion of illegitimacy. Another fourth-place finish for Gingrich, who got just 6 percent of the Maine vote, added emphasis to the weeklong streak of evidence that Newt’s campaign is fading while Santorum’s is surging.

With more than two weeks to go before the next round of primaries (Feb. 28 in Arizona and Michigan), it is impossible to rule out another stunning upheaval in this year’s turbulent Republican race. Already, the Romney campaign has begun re-targeting its brutal attack machine to take on Santorum, releasing negative “oppo” (opposition research) to the media, while the pro-Romney “super PAC” Restore Our Future buys Internet ads portraying Santorum as a proponent of pork-barrel spending. Being attacked by Team Mitt, however, could be seen as still more proof that Santorum’s surge has made him the leading conservative opponent to Romney. And with Gingrich now evidently on the ropes, Santorum may be positioned to emerge as the last man standing against Romney. How long he can remain standing is a question that will be answered in the days and weeks ahead.