The start of the 2012 Republican race for president was shaped by the 13 presidential debates of 2011 beginning on May 5. Gary Johnson and Buddy Roemer, both former Governors, were left out of most of the debates, leading to complaints of bias. On December 28, 2011, Johnson withdrew to seek the Libertarian Party nomination and on February 23, 2012, Roemer withdrew to seek the Reform Party and the Americans Elect nomination.

Two candidates from the 2008 presidential primaries, Mitt Romney and Ron Paul, ran again in the 2012 primary campaign. Mitt Romney was an early frontrunner, and he maintained a careful, strategic campaign that centered on being an establishment candidate. In the summer of 2011 he had a lead in polls with the support of much of the Republican electorate. However, his lead over the Republican field was precarious, owing to the entry of new candidates who drew considerable media attention. First congresswoman Michele Bachmann of Minnesota started her campaign in June and surged in the polls after winning the Ames Straw Poll in August, but she lost some of the momentum to Texas Governor Rick Perry shortly after he was drafted by strong national Republican support. He performed strongly in polls, immediately becoming a serious contender. But he lost the momentum following a poor performances in the September debates. As the third opponent to Romney's lead Herman Cain surged after the sixth debate on September 22. In November Cain's viability as a candidate was seriously jeopardized after several allegations of sexual harassment surfaced in the media, and he suspended his campaign on December 3, 2011, despite his unyielding denials of any misconduct.

In November as Herman Cain's campaign was stumbling former Speaker of the House Newt Gingrich asserted himself as the fourth leading opponent to Romney. It was a comeback for Gingrich after his campaign had suffered under serious staff problems just weeks after he had entered the race in May. But in the few weeks before the Iowa caucus, Gingrich's lead quickly began to evaporate. Iowans were bombarded with over $4.4 million in negative advertising on Gingrich from super PACs sympathetic to Mitt Romney and others. So on the eve of the Iowa Caucus, the first contest, there was no clear and strong frontrunner.

Background The U.S. economy suffered a recession from 2007 to 2009; median incomes fell for Americans, and unemployment, while falling from a high of 10.1% in October 2009, has remained above 8% so far through Obama's term in office. Polling showed voters who approved of his "handling of the economy" fell from 60% at the start of his term to the mid-30s by 2011. Since 2008, the Republican Party has experienced big gains in white voters, including younger and poorer Whites who trended Democratic. The results of the 2010 census also reduced the influence of traditionally blue states in the electoral college.

Polling found that Americans were increasingly frustrated with the U.S. government as a whole, and the Republican Party shared in those high disapproval ratings. In particular, although the majority of Americans felt Obama did not have a successful plan to bring jobs, they trusted Congress even less to create them. The House of Representatives, now with a substantial Republican majority since January 2011, refused to raise taxes and was engaged in a lengthy dispute over the debt ceiling. House Speaker John Boehner led negotiations with President Obama over raising the debt ceiling. The Tea Party movement, which was active in political town hall meetings, was opposed to raising the ceiling and also saw its support plummet as a result from the aftermath of the dispute. LGBT issues have been one of the major discussion topics among candidates. Amid intense debates, almost all Republican candidates have opposed same-sex marriage, expressing support for "traditional marriage" between a man and a woman. Only Jon Huntsman has supported civil unions. Newt Gingrich, Rick Santorum and Rick Perry have particularly spoken out strongly against gay marriage. Ron Paul has said that he does not believe that the government should enforce a definition of marriage. Santorum has opposed gay adoption, Gingrich and Herman Cain have described being gay as "a choice", and Bachmann has described gays as having a "sexual dysfunction".

Concerns about the security and support of Israel had also been apparent in the lead-up to the 2012 elections, affecting Jewish support for both Obama and the Republican Party. The nuclear armament of Iran was a political issue during the Republican primary, and all candidates opposed Iran acquiring nuclear weapons. Romney, Gingrich, Santorum, Perry, and Bachmann all took hawkish stands on Iran, and advocated for military strikes on Iranian nuclear facilities if other means of stopping Iran's attempt to develop nuclear weapons failed; Paul opposed both military action and economic sanctions.

A record number of advocacy group pledges were signed by Republican candidates this election cycle. The pledges candidates promised included social issues and fiscal policy. Every major Republican candidate has promised to repeal the Patient Protection and Affordable Care Act (PPACA) if elected president in 2012. Rick Santorum was an enthusiastic supporter of pledges, and was called a "Super Pledger" for his participation and defense of the practice. Jon Huntsman declined to sign any pledges, making him the only candidate in the 2012 cycle without one. The Susan B. Anthony List released a pro-life pledge signed by several candidates but not Romney. Pledges against same-sex marriage from the National Organization for Marriage and the Family Leader were signed by several to affirm that they would uphold the Defense of Marriage Act and prevent federal recognition of state marriages. The Family Leader's pledge was highly controversial for its statements about Muslims, slavery and pornography. Rick Santorum and Michele Bachmann signed the pledge, which also included a clause for the candidate to pledge to stay faithful to his or her spouse. Bachmann denied her pledge included the slavery language, despite insistence by the Family Leader that she received the full document. Santorum said he was "taken aback initially" when reading the document, but signed. Candidates also signed promises to push for a balanced budget amendment (the pledge was released by the group Let Freedom Ring), to reduce the national debt (), and to prevent any tax increases (Americans for Tax Reform).

Spring: Invisible primary

The race for the Republican primaries began slowly in 2011. Gallup polls found that historically the Republican Party had a clear front-runner by March.

In February and March 2011, the Republican candidates, as well as the party as a whole, were involved in a discussion on radical and political Islam. The Republican Party courted Muslim voters during Bush's 2000 campaign but had lost nearly the entire demographic by 2008. In the 2012 cycle, the supposed threat of Sharia law in the United States became a political issue. Speculated candidate Mike Huckabee made statements criticizing Islam. Rick Santorum was noted as saying Sharia law was "evil". He also said that American history books were corrupted, and that the Crusades were not an act of aggression by the Christians.

When Herman Cain was asked if he would appoint a Muslim to his Cabinet as president, he said, "I will not. And here's why. There is this creeping attempt, this attempt, to gradually ease Sharia law and the Muslim faith into our government. It does not belong in our government. This is what happened to Europe. And little by little, to try to be politically correct, they made this little change. They made this little change. And now they've got a social problem that they don't know what to do with hardly." The phrase "creeping Sharia" became a political catchphrase.

Republican enthusiasm for the field of candidates was weak in April, and polling found few Americans could even name the Republican contenders. Considerable media attention was given in April 2011 to Donald Trump, who considered running for the nomination and repeatedly criticized Obama, saying his policies were failing the U.S. economy. Trump said the United States was suffering in the global economy because of poor trade deals, saying "I think the biggest threat is that our jobs are being stolen by other countries. We’re not going to have any jobs here pretty soon." He pointed to the Chinese economy in particular and proposed a 25% tariff on Chinese imports to solve the trade discrepancy between the U.S. and China. Trump seized the issue of conspiracy theories about whether Barack Obama was an American citizen and was vocal in insisting that Obama show his "real" birth certificate. On April 28, Obama released his long form birth certificate. Trump never officially declared or filed an FEC report, and made it clear on May 15 that he would not be running for the GOP nomination.

Governors Mitch Daniels, Chris Christie and Haley Barbour all decided not to run in May, citing family concerns. In May, Newt Gingrich joined the race, but his credibility suffered a setback one week later, after referring to Ryan Plan's budget plan, which was popular budget among Republicans, as "Right-wing social engineering". One month later, his entire senior staff quit en-masse, citing personal difficulties with Gingrich, known to be highly-independent and un-choreographed. Gingrich struggled in polling until September 2011.

With few declared candidates, sponsoring news organizations postponed many of the debates in 2011. In the first debate, held on Fox News, candidates were asked for their opinion on the 2011 United States debt-ceiling crisis. Host Bret Baier asked candidates if they would agree to raise taxes by $1 for each new $10 in budget cuts; each candidate refused, rejecting raising taxes. Ron Paul stood out from other candidates, arguing for ending the war on drugs to great applause. At the end of the debate, in which most of the leading candidates did not participate, a focus group assembled for Fox News declared Herman Cain the winner. Viewers said he articulated clearly and directly on conservative principles, and outshined Tim Pawlenty, who at the time was regarded as the only "top-tier candidate" in the debate. Cain succeeded in gaining some momentum, and his supporters were said to have the most enthusiasm for their candidate.

Summer: Draft movements

Two candidates from the 2008 presidential primaries, Mitt Romney and Ron Paul, ran again in the 2012 primary campaign. Mitt Romney was an early frontrunner, and he maintained a careful, strategic campaign that centered on being an establishment candidate. Time magazine predicted his approach would fail, saying the Republican Party had changed from "country-club aristocracy" to "pitchfork populism" in 2011. Republicans questioned Romney's commitment to conservative ideals, and often accused him of being a flip-flopper for his changing positions on issues such as state-mandated health care, abortion, climate change, and same sex marriage. Romney maintained a weak lead of 20% nationally throughout 2011, raising doubt that he was a "true frontrunner". He enjoyed a significant money advantage and had the highest name recognition in the field, and many voters found him to be the most "electable" in the general election.