With the Republican primary contenders largely set, some candidates -- and others who choose not to run -- were left by the wayside. In this gallery, we take a look at the hopefuls who said no and the remaining GOP ticket hopefuls.
The former governor of Massachusetts made his bid official on June 2 at Bittersweet Farm in Stratham, N.H. He criticized President Obama for failing to bring about an economic recovery during three years in office and pledged to make jobs a priority. Romney announced on April 11 that he was forming an exploratory committee.(ELISE AMENDOLA/AP)
Rick PerryThe longtime Texas governor formally announced he was running for president on August 13. He was immediately viewed as a front-runner of the GOP field, but has since cooled off among Republican voters.(JAE C. HONG/AP)
On May 11, Gingrich tweeted: "I am announcing my candidacy for president of the United States." The former House speaker became the first contender with GOP leadership credentials to make an official move toward the presidency when he announced on March 1 that he was forming an exploratory committee.
VIDEO: N2K: Where's Gingrich's Base?(CHET SUSSLIN)
Jon Huntsman"I'm a candidate for the office of president of the United States of America," Huntsman told supporters on June 21 at Liberty State Park in New Jersey. Initial political moves indicate Huntsman, a former Utah governor who served as President Obama's ambassador to China, is aiming to build a centrist coalition.
VIDEO: For Huntsman in 2012, His Weakness is Also His Strength(AP PHOTO)
Rep. Ron Paul, R-Texas, announced on May 13 on Good Morning America that he's in. This is the folksy libertarian's third run at the White House, the first being in 1988. Now 75, Paul espouses a platform of fiscal conservatism and limited government that may carry a heavier weight with voters.
VIDEO: Ron Paul on GMA: I'm Running(CHET SUSSLIN)
Michele BachmannAt the CNN-broadcast Republican debate on June 13, Rep. Michele Bachmann, R-Minn., stole the spotlight by making her presidential candidacy official onstage as the rest of the field looked on. Two weeks later, she formally kicked off her campaign in Waterloo, Iowa--her birthplace and the heart of the caucus state where she is expected to bet most of her campaign chips. Bachmann told the crowd that "We can win in 2012, and we will."
VIDEO: Bachmann Announces Presidential Bid(AP PHOTO)
Rick SantorumFormer Sen. Rick Santorum of Pennsylvania officially announced his plans to run for president on ABC's Good Morning America on June 6. "We're in it to win and very excited about what the future holds," Santorum said. "We've got a great team, and in the early-primary states we've got a lot of momentum."VIDEO: Santorum's Path(CHET SUSSLIN)
"First time to say it. 'I am running for President,'" former New Mexico Gov. Gary Johnson (R) said via Twitter on April 21. He also launched a campaign website. Although Johnson’s a long-shot candidate, he might give Paul a run for the libertarian vote: He supports the legalization of marijuana and civil unions.(JOE BURBANK/AP)
Buddy RoemerFormer Louisiana Gov. Buddy Roemer officially launched his presidential bid on July 21 in New Hampshire. During a speech at Dartmouth College, Roemer described his campaign as a war against the special interests that control Washington, The Daily Advertiser reported. "I run to reveal and challenge the control of the special interests over our nation's capital and demonstrate the freedom to lead that can only come from refusing their money."(GERALD HERBERT/AP)