Former Pennsylvania Senator Rick Santorum won the Republican presidential primaries in Alabama and Mississippi Tuesday, narrowly defeating former House speaker Newt Gingrich and former Massachusetts Governor Mitt Romney, who finished second and third, respectively, in the two states. The fourth candidate in the race, Texas Congressman Ron Paul, did not campaign in either state and trailed badly.

Santorum’s margin of victory was relatively narrow—35-29-28 in Alabama, 33-31-30 in Mississippi—and under the rules of the two state Republican parties, the three leading candidates will get roughly equal shares of the 84 delegates to the Republican National Convention chosen in the states.

Nonetheless, the twin victories for Santorum stalled the campaign of frontrunner Romney, who poured millions into the two states in an effort to finish off his two major rivals. Romney had the support of nearly all Republican state officials in Mississippi and most of those in Alabama.

According to exit polls, Santorum was leading among those who rejected the theory of evolution, those who claimed to believe Obama is a Muslim (50 percent of the voters), those who thought banning abortion the most important issue, and those who said a candidate’s religion was very important to them (a measure of anti-Mormon sentiment among the evangelical Christians who made up three quarters of the electorate).

One pre-election poll found that a quarter of likely Republican primary voters in the two states believed that interracial marriages should be illegal. These voters sided more with Gingrich, who has made thinly veiled appeals to racial prejudice a part of his campaign. Last week he gave a speech devoted to “states’ rights,” the banner under with Southern segregationists fought the civil rights movement of the 1950s and 1960s.

The two primaries continued the pattern of the 2012 campaign, which has seen voter turnout well below that of 2008. Barely 500,000 voted in Alabama, down more than 50,000 from four years ago. Voter participation in Mississippi was slightly up compared to 2008, but only because the primary four years ago took place after the nomination had already been decided. As a proportion of those eligible to vote, turnout in Mississippi was even lower than in Alabama.

Santorum’s victories in Mississippi and Alabama followed a much wider win in the Republican caucuses in Kansas, where a tiny turnout of barely 25,000 people delivered him nearly all of the state’s 40 delegates.

The outcome of the three contests raised the likelihood of a protracted contest for the Republican presidential nomination, possibly extending all the way to the convention in Tampa in early September—only two months before the general election.

In television interviews late Tuesday night, Gingrich rebuffed suggestions that his second-place finishes had made his campaign unviable. He said that because of new party rules establishing proportional representation and the presence of four contenders, no single candidate would be able to win an outright majority of the delegates.

In that event, he said, Romney would have failed to win the nomination and the anti-Romney majority would be compelled to come together to choose a candidate, either Santorum, himself or someone not currently seeking the nomination.

Santorum aides made similar arguments Monday during appearances on MSNBC and other cable channels, arguing that no candidate could obtain a majority.

The Romney campaign claimed that its delegate lead was still insurmountable, despite the embarrassing series of defeats. Romney was able to offset Santorum’s edge in Kansas by winning most of the delegates awarded in Wyoming as well as those selected in the Pacific island territories, such as Guam, whose residents are not allowed to vote for president but who can choose delegates to the conventions of the two big business parties.

Tuesday’s results in the deep South will not materially change the overall delegate count, since Romney won nearly as many delegates as Santorum there and was favored to win the Republican caucuses in Hawaii.

Television network projections suggested that Romney had the support of 480 delegates, compared to 237 for Santorum, 116 for Gingrich and 67 for Paul, with 1,144 delegates required to win the nomination.

As the campaign has continued and the Obama administration has moved further and further to the right, his Republican opponents have been compelled to adopt ever more extreme positions in order to outflank him.

Romney, in particular, has repudiated nearly all the policies he pursued as governor of Massachusetts from 2003 to 2006 in order to embrace a series of political litmus tests laid down by the ultra-right Tea Party elements.

The most recent example was his conversion on the issue of the minimum wage, which he supported in Massachusetts and even during his 2008 campaign for the Republican nomination, advocating indexing the wage to inflation. But in a television interview last week, he reversed himself, declaring, “There’s probably not a need to raise the minimum wage.” This coincided with an advertising blitz in Mississippi and Alabama where he sought to paint Santorum as pro-union and both Santorum and Gingrich as “soft” on spending.

In an interview on Fox Business Channel, he rejected the suggestion that Santorum would be a suitable vice presidential choice, saying, “Rick Santorum is not a person who is an economic conservative, to my right. I’m saying I’m a conservative, I give him credit for being a conservative, but not a fiscal conservative.”

Santorum, for his part, told the Gulf Coast Energy Summit, meeting in Biloxi, Mississippi Monday, that global warming was a “hoax,” and that carbon dioxide was not dangerous because it was beneficial to plants. He claimed, “Those living on or near the Gulf Coast in particular know the impact these extreme environmental positions can have on the region’s economy.” He made no reference to the BP oil spill, which devastated the region, including the Mississippi Gulf Coast, two years ago.

Gingrich sought to outdo his rivals in right-wing populist demagogy, basing his campaign on a promise to lower the price of gasoline to $2.50 a gallon, with ads showing Obama bowing to Saudi King Abdullah at a ceremony.