ABC News' Comprehensive Guide to Super Tuesday

March 6, 2012 -- The big day has arrived. Ten states hold their voting contests today in the mega-primary day known as "super Tuesday." Four-hundred and thirty-seven delegates are at stake tonight. The candidate who carries the bulk of states will gain a solid lead in delegates, not to mention some serious momentum to carry them through the rest of the month.

Each state presents its own set of challenges for the four remaining GOP candidates, but there are also places that play to each individual candidates strengths. The complete guide to how each state works, what's at stake, and what to watch is outlined below.

Alaska

Alaska is one of the three Super Tuesday states holding a caucus. Not surprisingly due to its geography, Alaska will be the holdout of Super Tuesday, the polls will close at midnight, and it's possible results will not come in until well into the day on Wednesday. The state offers 27 delegates, doled out proportionally. Mitt Romney won Alaska's caucus in 2008 with 44 percent of the vote.

Georgia

Georgia is the biggest delegate prize of Super Tuesday; 76 delegates will be awarded on a proportional basis in this state. Newt Gingrich is favored to win here; after all, he represented the state in Congress for two decades. However, that hasn't stopped the other candidates from making a play for the Peach state. Mitt Romney's super PAC, Restore Our Future, has spent roughly $1.4 million on ad buys in Georgia, running ads opposing Gingrich. Polling shows Gingrich with a comfortable lead in the state going into Tuesday's contest.

Idaho

Idaho is the second state holding a caucus on Super Tuesday. There are 32 delegates at stake. The state has a large Mormon population and so far in this primary season (as in 2008) that has behooved Romney. However, Ron Paul's ability to draw out supporters in a caucus format cannot be underestimated. He performed strongly here in 2008, with 24 percent of the vote (losing to John McCain, who took 70 percent.)

Massachusetts

Massachusetts may not exactly be the kind of conservative power boost that the candidates are looking for at this stage in the primary, but it offers 41 delegates total (awarded proportionally, as is the case with all of super Tuesday's states) and in a close race, a win is a win. Mitt Romney is expected to carry the state he represented as governor, and he will spend Tuesday night at his home in Boston. In 2008, Romney carried his state with a majority of the vote with 51 percent.

North Dakota

North Dakota is the third and final Super Tuesday state holding a caucus. There are 28 delegates at stake. Mitt Romney won this state in 2008 by receiving 36 percent of the vote. Ron Paul had a strong showing here in 2008 as well. He took 21 percent of the vote. Paul has been campaigning hard for North Dakota, even going so far as to chose to spend his time on Tuesday night in the state. Tuesday will be his third visit to this state.

Ohio

Georgia may have the biggest delegate prize, but Ohio is considered the real gem in the Super Tuesday crown. There are 66 delegates in Ohio and the candidate who carries the Buckeye state will have the ability to tout their victory in a key general election swing state.

Polls have showed Romney and Santorum in a close race here, and they're both fighting hard. Restore Our Future, the Super PAC supporting Mitt Romney has sunk roughly $2.7 million in ad buys into the Ohio media market. The Red, White and Blue Fund, the Super PAC supporting Rick Santorum has spent less, around $500,000 on ad buys but it's worth noting that Ohio is the only Super Tuesday state where the group has made television buys.

Rick Santorum faces a delegate disadvantage in the state however. Santorum failed to qualify for the ballot in three congressional districts; the 6th district, 9th and 13th. In spite of this, Santorum will actually be spending Tuesday night in Steubenville, Ohio, located in the 6th district.

Additionally, Santorum also failed to submit a full slate of delegates in another six congressional districts, meaning that Santorum will be ineligible to receive up to 18 of the state's 66 delegates.

Oklahoma

Oklahoma prides itself on being the reddest state in the nation. Because of this, the state will be largely ignored once the general election season rolls around, but in the primary, it's a hot commodity.

"All of our candidates are trying to be able to make the claim that they've closed the deal with the base and there's nowhere better for them to make that claim than if they win the reddest state in the country" Oklahoma Republican Party Chairman Matt Pinnell explained to ABC News. "If they win Oklahoma, they can say I'm conservative enough, the proof is in the pudding."

Oklahoma will award 43 delegates proportionally. Polls have showed Santorum performing well in the sooner state.

TennesseeTennessee will be another close state to watch on Tuesday night. Polling here has showed Santorum in the lead, though the size of that lead has narrowed over time. Romney has a great deal of "establishment" support here.

The state's governor, Bill Haslam, is chair of Romney's campaign in the state, and the state's senior Senator, Lamar Alexander, has also endorsed Romney. The Super PAC supporting Romney, Restore Our Future, has spent more than $1.3 million on ad buys in the state, and the vast majority of those ads attack Rick Santorum. There are 58 delegates at stake in the state where Mike Huckabee narrowly claimed victory in 2008, with 34 percent of the vote (McCain followed closely with 32 percent.) Tennessee is another jewel that Santorum and Romney would love to add to their bounty of winnings.

Vermont

Like its neighbor Massachusetts, Vermont is not exactly seen as a state that a Republican candidate wants to brag about winning. It is solidly Democratic, and viewed in popular culture as a bit of a haven for granola loving, tree hugging hippies. Not exactly the conservative base these candidates have been trying so hard to court. Nevertheless, every delegate counts, and Vermont will offer 17 of them. Romney is the favorite to win here.

Virginia

In any other year Virginia would be a huge contest for these GOP candidates; it offers 49 delegates, but the real reason for its importance lies in momentum. Many pundits argue that there is no path to a Republican White House that does not include a victory in Virginia in the general election, so the winner here would have a huge trump card in their back pocket. However, only two candidates, Mitt Romney and Ron Paul have qualified to be on the ballot so the stakes are a little lower here than they might be otherwise.

Mitt Romney is heavily favored to win here, but the question remains to whether he will be able to capture all 49 of the delegates.

Virginia's proportional allotment awards winner-take-all by congressional district, with their additional at-large delegates being awarded on a proportional allotment. If a candidate takes more than 50 percent of the vote, they will receive all of the at-large delegates.

With two candidates on the ballot that's practically a mathematical certainty, so it's possible that Mitt Romney could actually take a big prize here.

The portion of the state to watch is the southwestern area, around Roanoke, Blacksburg and Harrisburg.

Ron Paul has spent a lot of time campaigning in this part of the state, and the more conservative/libertarian demographics tend to yield good results for the Texas Congressman.