Rick Santorum and Mitt Romney split six states and dueled in an almost impossibly close race in Ohio on a Super Tuesday that stretched from one end of the country to the other in the most turbulent Republican presidential race in a generation.

Rick Santorum was drawing robust support Tuesday from the most conservative voters in Ohio's Republican presidential primary, according to early results of an exit poll of voters. He was also managing a modest lead over rival Mitt Romney among the state's blue-collar voters, whom he has targeted in his drive to slow Romney's march toward the GOP nomination.

WASHINGTON (Reuters) - Mitt Romney won the Republican presidential caucuses in Idaho on Tuesday, Fox News projected. With 12 percent reporting, former Massachusetts governor Romney had 78 percent support, to 11 percent for Texas Congressman Ron Paul, his closest competitor. (Reporting By Patricia Zengerle; Editing by Doina Chiacu)

WASHINGTON (Reuters) - Rick Santorum and Mitt Romney were virtually tied in the Ohio Republican presidential primary with 85 percent of the vote counted. Santorum, a former U.S. senator from Pennsylvania, was leading Romney by less than 3,000 votes. (Reporting by Deborah Charles; Editing by Doina Chiacu)

Republican Rick Santorum is back.

Rick Santorum has won North Dakota's Republican presidential caucuses, adding to his wins in Tennessee and Oklahoma.

Republican presidential candidate Ron Paul remained defiant Tuesday night in the face of no primary wins, rallying his fervent supporters to his signature causes of civil liberties and an overhaul of the country's monetary system.

WASHINGTON (Reuters) - Rick Santorum, a former U.S. senator from Pennsylvania, won the Republican presidential caucuses in North Dakota on Tuesday, CNN projected. Congressman Ron Paul of Texas was in second place and former Massachusetts Governor Mitt Romney was in third with 78 percent of the votes counted, CNN said. Newt Gingrich, a former speaker of the U.S. House of Representatives, was in fourth place. (Reporting By Patricia Zengerle; Editing by Vicki Allen)

With a vital win in the Georgia primary Tuesday, Republican presidential candidate Newt Gingrich quickly looked ahead to the next round of contests, promising yet another comeback for what he called "the power of ideas."

WASHINGTON (Reuters) - Former U.S. Senator Rick Santorum held a slight lead over Mitt Romney with half the vote counted in the Republican presidential primary in Ohio, the most closely watched state to vote on Super Tuesday. With 50 percent of the vote counted, Santorum was leading Romney 39 percent to 36 percent. (Reporting by Deborah Charles; Editing by Vicki Allen)

Republican Rick Santorum says "this was a big night tonight" and is calling the day's biggest race in Ohio "too close to call."

Rick Santorum has won the Republican presidential primary in Oklahoma.

Santorum wins Republican presidential primary in Oklahoma

Rick Santorum’s win in Tennessee came in one of the most conservative, most heavily evangelical, most religion-focused and most anti-abortion Republican primary electorates to date – all among the groups on which the former Pennsylvania senator has focused his appeal. If Santorum’s win was less...

WASHINGTON (Reuters) - Mitt Romney held a slim lead over Rick Santorum in the Republican presidential primary with 12 percent of the vote counted in Ohio, the most closely watched of the 10 nominating contests being held on Super Tuesday. Romney was leading 39 percent to 37 percent for Santorum, with 12 percent of the vote counted. A victory in Ohio and a good showing elsewhere would make Romney, a former Massachusetts governor, the favorite to win the nomination. Santorum, a former U.S. senator from neighboring Ohio, has been campaigning as the conservative alternative to Romney. ...

Republican presidential candidate Newt Gingrich will receive Secret Service protection starting Wednesday.

Mitt Romney rolled to primary victories in Virginia, Vermont and home-state Massachusetts on Super Tuesday, reaching for a decisive advantage in the most turbulent race for the Republican presidential nomination in a generation.

WASHINGTON (Reuters) - Rick Santorum won the Republican presidential primary in Tennessee on Tuesday, U.S. television's NBC and CNN networks projected, defeating rival Mitt Romney. (Reporting By Patricia Zengerle; Editing by Vicki Allen)

The Super Tuesday results are coming in and candidates vying for the Republican presidential nomination are taking time to address their supporters.

Watch live video of the contenders speaking on election night.

Click here for HuffPost's live blog coverage of Super Tuesday.

The Republican presidential primary had its biggest day yet on Tuesday, when 10 states went to the polls to vote for the GOP nominee.

With 419 delegates at stake, Super Tuesday was crucial for the four remaining candidates, Mitt Romney, Rick Santorum, Newt Gingrich and Ron Paul. Naturally, political observers had plenty to say about the results.

Here is a look at what people are saying about Super Tuesday on Twitter. Scroll farther down to follow The Huffington Post's Twitter dashboard.

(Reuters) - The race to win the Republican Party's presidential nomination to challenge President Barack Obama reaches a new intensity on "Super Tuesday" when 10 U.S. states, including Oklahoma, hold primaries and caucuses. Here are some facts about the Oklahoma Republican primary: * Polls show former U.S. Senator Rick Santorum of Pennsylvania, a social conservative, ahead of former Massachusetts Governor Mitt Romney, the overall front-runner. The state will award 43 delegates, mostly through a proportional formula. ...

(Reuters) - The race to win the Republican Party's nomination to challenge President Barack Obama in the November general election reaches a new intensity on "Super Tuesday" when 10 U.S. states, including Massachusetts, hold primaries and caucuses. Here are some facts about the Massachusetts Republican primary: * Mitt Romney, a former one-term governor of the northeastern state, is expected to cruise to victory on his home turf. ...

Mitt Romney has won Republican presidential primaries in Vermont and Virginia, and Newt Gingrich has won in his home state of Georgia.

Former Massachusetts Gov. Mitt Romney jumped to an early lead in the race for Super Tuesday delegates by winning the Republican presidential primary in Virginia.