Mitt Romney on the trail

Mitt Romney, the former Massachusetts governor and unsuccessful 2008 candidate, has a lot going for him in his 2012 presidential run: He has worked hard to establish his conservative credentials following his relatively moderate tenure as Massachusetts governor, and he has consistently scored among the top two contenders in GOP presidential polls. But Romney has liabilities, too: His Mormon faith remains a potential roadblock to some voters, and some see him as a political opportunist. Plus, the health care bill he signed into law in Massachusetts is already proving to be a political problem -- especially since it looks eerily familiar to the national law President Obama passed in 2010. In the following slides, CBSNews.com takes a look at Romney's recent time on the campaign trail.

Romney addresses the Detroit Economic Club at Ford Field in Detroit, Friday, Feb. 24, 2012.

Former U.S. Sen. Rick Santorum, left, and former Massachusetts Gov. Mitt Romney talk after participating in a debate sponsored by CNN and the Republican Party of Arizona at the Mesa Arts Center Feb. 22, 2012, in Mesa, Ariz.

Mitt Romney, Michigan — AP Photo/Gerald Herbert

Romney speaks at a campaign rally in Kentwood, Mich., Wednesday, Feb. 15, 2012.

Romney speaks at a caucus, Saturday, Feb. 11, 2012, in Portland, Maine.

Ben Garvin ,AP Photo/The St. Paul Pioneer Press

Romney and his wife Ann are "glitter bombed" as they enter an campaign event at Freightmasters Inc. in Eagan, Minn., on Wednesday, Feb. 1, 2012. It happened again after he spoke, as he was making his way along the rope lines greeting supporters.

Romney speaks to supporters at his Nevada caucus night victory celebration in Las Vegas, Saturday, Feb. 4, 2012.

Romney greets supporters at his Florida primary night rally in Tampa, Florida, on January 31, 2012. Romney won the Florida primary by a substantial margin.

Romney and former presidential nominee U.S. Sen. John McCain (R-AZ) hold a campaign town hall meeting at the Peterborough Town House January 4, 2012 in Peterborough, New Hampshire. McCain announced his endorsement of Romney the day after Romney beat former U.S. Senator Rick Santorum by only eight votes in Tuesday's 'first in the nation' Iowa Caucuses.

Mitt Romney, Iowa — AP Photo/Charlie Neibergall

Romney speaks during a campaign stop at Giese Manufacturing, Monday, Nov. 7, 2011, in Dubuque, Iowa.

Romney speaks with supporters after the debate at the Benjamin Johnson Arena, Saturday, Nov. 12, 2011 in Spartanburg, S.C.

Romney makes a phone call as he greets and thanks Fairfax County Republican Committee phone bank volunteers at their headquarters in Fairfax, Virginia, October 26, 2011.

Romney works with volunteers making calls while visiting his Romney For President New Hampshire Headquarters in Manchester, N.H., Oct. 22, 2011.

Romney files the paperwork necessary to be on the New Hampshire primary ballot October 24, 2011 at the Statehouse in Concord, New Hampshire. Romney picked up the endorsement of former New Hampshire Governor John Sununu (R) as well.

Chris Christie and Mitt Romney — Photo by Justin Sullivan/Getty Images

Romney shakes hands with NJ Governor Chris Christie after Christie endorsed him on October 11, 2011 in Lebanon, New Hampshire.

Romney signs an autograph on a paperback book of his new jobs and plan for the economy after a town hall meeting, Sept. 14, 2011, in Sun Lakes, Ariz.

Romney speaks to supporters during a rally at the American Polish Cultural Center on November 10, 2011 in Troy, Michigan.

Romney talks to Jie Fang Lu during a campaign stop at New England Small Tube in Litchfield, N.H., Aug. 15, 2011.

Republican presidential candidate former Massachusetts Gov. Mitt Romney greets the crowd outside the New Hampshire Statehouse after filing the necessary paperwork to be on the New Hampshire primary ballot, October 24, 2011 at in Concord, New Hampshire.

Former Massachusetts Gov. and Republican presidential hopeful Mitt Romney along with Nevada Lt. Gov. Brian Krolicki (at right) bend down to take photos with supporters as Romney opens his Nevada campaign headquarters, October 17, 2011, in Las Vegas, Nevada.

Former Massachusetts Gov. and Republican presidential candidate Mitt Romney speaks on trade issues on the Microsoft campus, October 13, 2011 in Redmond, Washington.

Romney greets supporters after addressing the Conservative Political Action Conference (CPAC) at the Marriott Wardman Park on February 11, 2011 in Washington, D.C. Romney was one of about a dozen potential Republican presidential hopefuls who made appearances at CPAC, the biggest gathering of conservative activists in the country. In his remarks at the convention, the former Massachusetts governor slammed President Obama's economic policies, arguing that modern job fairs and unemployment lines are Obama's "Hoovervilles."

Romney speaks during a rally for Rick Scott, then the Republican gubernatorial candidate for Florida, on October 1, 2010. Scott, a former health care CEO, was narrowly elected to the governorship after a tight race against Democrat Alex Sink.

Romney joins U.S. Sen. John McCain as he speaks during a town hall meeting at a campaign stop in Mesa, Arizona on June 4, 2010. McCain, who was seeking a fifth term in the Senate, ultimately prevailed over former congressman and radio personality J.D. Hayworth during the primary.

Romney talks with potential supporters at an Iowa Christian Alliance House Party on November 30, 2007, in Dubuque, Iowa. Romney ultimately saw his once-strong leads in Iowa fade in the face of strong support for Mike Huckabee, a former governor of Arkansas.

Romney prepares for a televised interview with CBS' "Face the Nation" at his hotel on January 13, 2008 in Battle Creek, Michigan.

Republican presidential candidates (L-R) then-U.S. Sen. Sam Brownback (R-KS), Romney, former New York City Mayor Rudolph W. Giuliani and U.S. Sen. John McCain (R-AZ) take to the stage to participate in a GOP presidential debate at Saint Anselms College on June 5, 2007 in Manchester, New Hampshire.

Romney signs into law a health care reform bill during a ceremony at Faneuil Hall on April 12, 2006 in Boston, Massachusetts. U.S. Sen. Edward Kennedy (D-MA) and others joined the then-governor for the signing of the bill, which made Massachusetts the first state in the country to require all residents to have health insurance. Romney has in recent months taken heat by Republicans for the legislation, which has been likened to President Obama's health care reform law.

Romney and the late U.S. Sen. Edward Kennedy (D-MA) follow Paul Morrill, who carries Massachusetts' health care reform bill, before Romney signed it into law during a ceremony at Faneuil Hall April 12, 2006 in Boston, Massachusetts.

Romney talks to Olympic Gold Medalist Carl Lewis (who is now running for office himself) prior to giving their testimony before a Senate Commerce Competition Subcommittee on Capitol Hill May 4, 2004, in Washington, D.C. Romney and other witnesses talked about lessons learned from security at past Olympic games.

Romney speaks during a debate hosted by CNBC and the Michigan Republican Party at Oakland University on November 9, 2011 in Rochester, Michigan.

Former President George W. Bush addresses the audience at a $1 million fundraiser for Romney, then the Republican Massachusetts gubernatorial candidate, in 2002 in Boston, Massachusetts. Romney ultimately won the race and served as governor until 2007.

Romney walks up the ramp to his airplane at Jackson Atlanta International Airport as he heads to another leg of his campaign on February 4, 2008 in Atlanta, Georgia.

Romney looks on as 1980 Men's Hockey gold medalist Mike Eruzione (L) and 1998 Freestyle aerial skiing gold medalist Nikki Stone (C) raise the 2002 Olympic Torch during ceremonies to unveil the torch on February 21, 2001 at the U.S. Capitol. The torch was patterned after an icicle, symbolizing winter sports and the theme of the games, which was 'Light the Fire Within.'

Romney celebrates with children from the 'Children's Dance Theater' in Salt Lake City, Utah, on May 15, 1999, during the unveiling of three new mascots for the Salt Lake 2002 Winter Olympics. Utah schoolchildren were invited to enter a contest to select the names of the three mascots.