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By MICHAEL FALCONE ( @michaelpfalcone ) and AMY WALTER ( @amyewalter )

Political rivals can smell vulnerability from a mile away. And this week, Mitt Romney's detractors are looking to feast on his weakness after his triple defeat on Tuesday night.

Rick Santorum is attempting to use the opportunity as a way to get back into the game and the candidate and his campaign is playing up the David vs. Goliath angle.

"He had the organization and the money," Santorum said of Romney while campaigning in Texas yesterday, "and it didn't work out so well for him, did it?"

It's an important moment for Santorum who has been huddling with advisers to map out a strategy for the primary contests ahead. Yesterday Santorum signaled he would challenge Romney on his home turf - focusing on Michigan, which holds its nominating contest on Feb. 28.

Romney's inability to seal the deal also comes as conservatives from around the country are convening the annual Conservative Political Action Conference, known as CPAC, in Washington, DC. The three-day event, which begins today, will feature speeches by Romney, Santorum and Newt Gingrich and will no doubt be a chance for the right to air some of its grievances with the Romney, who still looks like the most likely contender to capture the Republican nomination.

In fact, that airing has already started.

"Playing it safe, which Romney tends to do, is not going to get it for him," Sen. Jim DeMint, R-S.C., told Politico's Jonathan Martin. DeMint was just one of several conservative U.S. senators who echoed similar concerns about Romney. http://politi.co/wQhZfF

And Dick Armey, a major figure in the Tea Party movement and former U.S. Congressman, acknowledged in an interview with The New York Times' Jeff Zeleny that "grass-roots activists understand the importance of beating Obama, but they are also insisting on conservative reliability." http://nyti.ms/wToTPR

Democrats are salivating over Romney too.

The Democratic National Committee is hosting a conference call today to expose what they call Romney's "flip flop concerning mandatory contraception coverage" and they are also out with a new web video today lambasting the former Massachusetts governor for holding a high-dollar fundraiser tonight in Washington, DC.

"Featuring influencers with deep ties to Wall Street, big oil, insurance and other industries, the event gives a look into the web of influence in Mitt Romney's world," the DNC writes in a note accompanying the clip. WATCH: http://bit.ly/yL0Lk2

CPAC PRIMER. Courtesy of Yahoo News' Chris Moody: "The Conservative Political Action Conference (CPAC), the ultimate hajj for anyone who ever hung a poster of William F. Buckley in their dorm room or read Barry Goldwater's Conscience of a Conservative for fun. Starting Thursday, thousands from around the country will gather at the Marriott Wardman Park Hotel in northwest Washington for three days of panels, strategy sessions and booze-filled after-parties. … News is made at CPAC almost every year: In 2008, Mitt Romney announced that he was ending his bid for the White House. Many of the movement's heaviest hitters are scheduled to attend this year, including Florida Sen. Marco Rubio, former Alaska Gov. Sarah Palin, and three of the four candidates for the Republican presidential nomination-Ron Paul is sticking to campaigning this year. This has major implications for the conference's much-ballyhooed presidential straw poll. For two consecutive years, Ron Paul has won the straw poll, in part because his campaign has offered free and heavily subsidized conference registrations to students, to the ire of some CPAC officials, who see Paul as an outlier. (Paul turned down an invitation to speak this year, citing his duties on the campaign trail. His son, Kentucky Sen. Rand Paul, is slated to address the conference on Thursday." http://yhoo.it/zHLWA3

THE BUZZ

RICK SANTORUM DRAWS MASSIVE TEXAS CROWD. Standing in front of a massive crowd at a rally in Plano, Texas, Rick Santorum unleashed criticism of Barack Obama and threw out some campaign red meat to supporters hungry for it, telling them the president has an "overt hostility to faith," ABC's Shushannah Walshe reports. "(He's) trying to weaken them, churches, trying to say that anybody who believes in the values of the Judeo Christian policies," Santorum said to about 2,000 people in a converted barn, one of his largest audiences of the campaign. He told the audience at the raucous rally that Obama is restricting religious freedoms in this country, and even that a situation like the French Revolution could happen in America. As he spoke supporters yelled, "We want Rick!" and "We want you!" throughout the speech. "They are taking faith and crushing it. Why? Why? When you marginalize faith in America, when you remove the pillar of God given rights then what's left?" Santorum asked and an audience member offered, "Communism!" "The French Revolution," Santorum answered. "What's left is a government that gives you rights. What's left are no unalienable rights. What's left is a government that will tell you who you are, what you'll do and when you'll do it. What's left in France became the guillotine. Ladies and gentlemen, we are a long way from that, but if we do follow the path of President Obama and his overt hostility to faith in America, then we are headed down that road." http://abcn.ws/AfSwgX

NOTED: The Romney campaign plans to continue to push its anti-Santorum narrative today. According to Team Romney, "Oklahoma State Treasurer Ken Miller and State Auditor Gary Jones will hold a press conference call to discuss Sen. Rick Santorum's enthusiastic defense of earmarks and support of reckless spending." The call will take place at 12:45 p.m. ET.

TOP MICHIGAN REPUBLICAN PREDICTS 'SUCCESSFUL' PRIMARY FOR ROMNEY. "I think that the Romney campaign will be successful in Michigan," the state's Republican Party Chairman Bobby Schostak told reporters at a briefing on Wednesday. "I don't see a scenario where they're not." Michigan holds its nominating contest on Feb. 28 - just under three weeks from now and on the same day as the Arizona primary. In an interview on MSNBC Wednesday morning, Santorum called Michigan "a great place for us to plant our flag and talk about jobs and manufacturing." Chairman Schostak acknowledged that Santorum has "got a bit of momentum now," but he noted Romney's home-field advantage in the state where he grew up and where his father, George Romney, served as governor. "Michigan is kind of home turf for the Romney family and so he's got a bit of a uphill battle in that regard just to get himself situated and positioned," Schostak said of Santorum, adding that only time would tell whether going three-for-three in Tuesday night's contests would be "enough to overcome the Romney family legacy in Michigan." http://abcn.ws/zIiv8z

L.A. MAYOR SLAMS ROMNEY ON IMMIGRATION. Los Angeles Mayor Antonio Villaraigosa pounced on Mitt Romney's immigration stance Wednesday night before a crowd of Washington, D.C., lawmakers and officials honoring the mayor for his public service, ABC's By Mosheh Gains reports. "For the first time in modern memory, a major political party is poised to nominate a presidential candidate who has abandoned immigration reform and instead advocates self-deportation," he said. Villaraigosa, who was presented with the 2012 Edward R. Roybal Award for Outstanding Public Service by the National Association of Latino Elected and Appointed Officials, didn't mention Romney by name, but called out the GOP front-runner for rejecting past bipartisan efforts on immigration reform. "Democrats and Republicans have recognized that our immigration system is broken and that it needs to be fixed.  Now they haven't always agreed on the route but they've agreed on the destination.  He added, "Unfortunately, now the likely Republican nominee for president has clearly rejected this rough consensus." http://abcn.ws/zbvA0Z

U.S. CHAMBER OPENS AD BLITZ. "The U.S. Chamber of Commerce is launching a $10 million campaign Thursday to support the election of 20 mostly Republican congressional candidates, a sign that it isn't only the presidential race that could see record spending this year," the Wall Street Journal's Brody Mullins notes. "The U.S.'s biggest business lobby plans to run ads in 12 House and eight Senate races as part of an effort referred to internally as 'Advance and Protect.' The goal is to help Republicans win a majority of seats in the Senate while protecting the GOP majority in the House. Most of the Senate races targeted by the Chamber are those Republicans hope will bring them the four seats needed to win control, including in Wisconsin and Missouri where Republicans haven't even picked a candidate. The ads in those states, which criticize Rep. Tammy Baldwin of Wisconsin and Sen. Claire McCaskill of Missouri, are designed to weaken the Democratic candidate." http://on.wsj.com/yHAU5x

OBAMA TRUMPS ROMNEY WITH SMALL DONORS. In the scramble for campaign cash, President Obama has proved once again that he's king,  at least among  American small-dollar donors, ABC's Devin Dwyer notes. Nearly half  -  48 percent - of Obama's $118 million haul in 2011 came from individuals giving $200 or less, according to a new analysis by the Campaign Finance Institute, a nonpartisan group. Small-donors made up only 9 percent of the 2011 fundraising total for Mitt Romney. But it's on the other end of the donor spectrum that Romney holds more sway: He gathered 82 percent of his funds from donors giving  $1,000 or more, the Campaign Finance Institute found.  Those high-dollar donors comprise just 28 percent of Obama's total. Looked at in absolute sums, Obama raised more money from small donors last year - $56.7 million to $56.3 million - than Romney collected from all donors combined. Michael Malbin, executive director of the Campaign Finance Institute, said the figures could represent a significant advantage for Obama beyond the bottom line. "Because small donors can give again, and may be willing to serve as campaign volunteers, successful small-donor fundraising can serve a political purpose that goes well beyond the reported dollars," Malbin said in a statement. http://abcn.ws/wiIk4A

KEEP AN EYE ON THE CALENDAR. Until Feb. 28, when Michigan and Arizona hold primaries, the only contests are in Maine and Washington-caucus states where precincts will vote over date ranges suggested by the state parties. ABC's Matt Negrin takes a look at how the GOP voting calendar lines up in the near future. Despite Mitt Romney's losses on Tuesday, he's still facing a run of states where he performed well in 2008. http://abcn.ws/zF7G8j

WHO'S TWEETING?

@jpodhoretz : Romney can go negative, and should to some degree, but if he doesn't figure out how to inspire, he's toast.  nyp.st/yUOD7H

@keachhagey : WaPo and WSJ front pages lead with nearly identical praying Santorum photos taken inches apart. yfrog.com/j60jg6j

@HotlineJosh : Must-read:  @HotlineSean and  @HotlineKevin rundown of which Senate Dems are breaking w/ Obama on contraceptive mandate hotlineoncall.nationaljournal.com/archives/2012/…

@JenniferJJacobs : #CPAC top guy Al Cardenas tells reporters this a.m. that no campaign has tried to stack deck for straw poll this year. "We would know."

@CPACnews : Could no make it to DC  #cpac no fear watch the live feed online. conservative.org/cpaclive/

POLITICAL RADAR:

- Rick Santorum will hold rallies with supporters in Oklahoma City and Tulsa, Oklahoma

- Mitt Romney will attend a private fundraiser in Washington, D.C.

- Newt Gingrich and Ron Paul are off the campaign trail for the day.

-ABC's Joanna Suarez

Check out The Note's Futures Calendar:  http://abcn.ws/ZI9gV

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