Republicans greatly extended Mitt Romney's lead over his rivals for the party's presidential nomination in multiple Super Tuesday contests that underscored Rick Santorum's evangelical appeal and gave Newt Gingrich a tenuous new lease on life.
Races held in 10 states from Georgia to Alaska enabled Mr. Romney to amass the bulk of the more than 400 delegates up for grabs as he eked out a critical win in Ohio, edging past Mr. Santorum in a key Rust Belt state for the second time in as many weeks.
While Mr. Romney could not clinch the GOP race on Super Tuesday, and while none of his rivals is likely to drop out in its wake, he made the likelihood of anyone else securing the 1,144 delegates needed for the nomination look increasingly remote.
Indeed, if Mr. Romney cannot win the nomination on the strength of his personality or policies, he aims to secure it through a mathematical war of attrition. His operatives have invoked President Barack Obama's victory over Hillary Clinton in the 2008 Democratic primary, which ultimately came down to the Obama team's quantitative strategy.
Mr. Gingrich easily won Georgia, the state he long represented in Congress, giving him the moral justification for staying in the race. But his third place finish in Tennessee and defeat in Oklahoma exposed the feebleness of his so-called Southern Strategy.
Still, Mr. Gingrich greeted supporters in his former congressional district – dozens of them waving signs touting their candidate's signature promise of $2.50-a-gallon gasoline – vowing to write "a new chapter in the fight for the soul of the Republican Party."
"There are lots of bunny rabbits who run through," he said, invoking the short-lived surges of Michele Bachmann, Rick Perry and Herman Cain. "I'm the tortoise."
Mr. Santorum's strength among evangelical Christians propelled him to the top in Tennessee, Oklahoma and North Dakota. But his convincing victories there contrasted with his stalled momentum in Ohio, where he staked his campaign on winning working-class voters.
The ex-Pennsylvania senator played up his roots as a steel-town native and grandson of a coal miner and, barely a week ago, enjoyed a double-digit lead over Mr. Romney in Ohio. By voting day, the two were in a dead heat.
Still, exit polls showed Mr. Santorum soundly beating Mr. Romney among middle-income earners, illustrating the ongoing challenge the ex-Massachusetts governor faces in capturing a cohort that will be crucial in determining the outcome of the general election.
Mr. Romney swept Massachusetts, where he was a one-term governor until 2007, and Virginia, where he and Texas Congressman Ron Paul were the only ones on the ballot.
In all, Mr. Romney gained victories in six states. The other states he won were Alaska, Vermont and Idaho.
But even where Mr. Romney did not win, he made sure he racked up plenty of delegates. For instance, he finished second in most districts in Georgia and Tennessee. Those states award one delegate to the runner-up in each of their combined 23 districts.
The Romney campaign's vaunted organizational and financial strength is likely to prove its worth again and again in coming weeks. His rivals will struggle to compete on the same scale.
Mr. Gingrich's campaign has little money of its own and a Super PAC that supports him is relying on infusions of cash from Las Vegas casino magnate Sheldon Adelson to run pro-Gingrich ads in Mississippi and Alabama in advance of next week's primaries there.
Mr. Santorum is similarly hobbled by a rudimentary campaign machine whose weaknesses resulted in his failure to qualify for the Virginia primary and left him off the ballot in three of Ohio's 16 congressional districts.
If any doubt remained that the general election campaign is fully engaged, Mr. Obama dispelled it by upstaging his most likely Republican rival in November with a Super Tuesday press conference during which he denounced Mr. Romney's "big talk" on Iran without directly naming his rival.
Earlier in the day, Mr. Romney had addressed the pro-Israel lobby American Israel Public Affairs Committee in Washington, where he skewered Mr. Obama's "naïve outreach" toward Iran.
The ex-Massachusetts governor went further in an op-ed in the Washington Post, calling Mr. Obama "America's most feckless president since [Jimmy]Carter" who "fretted in the White House" as the Iranians made rapid progress toward obtaining a nuclear bomb.
"This is not a game," Mr. Obama charged. "If some of these folks think that it's time to launch a war, they should say so. And they should explain to the American people exactly why they would do that and what the consequences would be."
Back in Georgia, there was little love for the state's adoptive son at a polling station in Midtown Atlanta, home to the sleek office towers, upscale restaurants and Renzo Piano-designed High Museum of Art that have made the city a showpiece of the New South.
Indeed, many Democrats took part in the Republican primary out of disdain for Mr. Gingrich. They voted for Mr. Romney, seeking to shrink Mr. Gingrich's margin of victory and prevent him from walking away with all of Georgia's 76 delegates.
"I'm a Democrat and I can't stand Gingrich. It's a protest vote against him," retiree Walter George, 77, said after casting a ballot for Mr. Romney.
Jack Bertram, 65, another Democrat who participated in the GOP primary, said he voted for Mr. Romney because the idea of a Gingrich or Santorum presidency "horrified" him.
"I would hope Obama is victorious in November. But if the alternative is to be chosen, I would hope that it would be Romney," he said. "I would be horrified if one of the other alternatives was to be successful."
For independent voter and commercial artist James Way, 43, the choice came down to picking the Republican candidate best positioned to beat Mr. Obama in November.
"Gingrich is smart but I just don't think he has a chance of winning," reasoned Mr. Way, who likened Mr. Romney to "Obama-light" but voted for him anyway.
Still, Mr. Gingrich could count on overwhelming support in rural Georgia and in the suburbs north of Atlanta, which include the 6th Congressional District he represented for two decades until 1999. Overall, he carried Georgia by 25 percentage points.
In one state, at least, the posters reading Newt-a-Mania were accurate.