Get super excited for Super Tuesday, the big day in the US primaries when 10 states vote on who will be the next Republican nominee in a presidential campaign against Barack Obama.

Millionaire businessman Mitt Romney has been the Republican front runner for months but the race isn’t over yet, with Ron Paul, Rick Santorum and Newt Gingrich all campaigning fiercely. It’ll be six more weeks until the final Republican nominee is certain.

Today is crucial for nominees, notes The Washington Post:

“Super Tuesday might give former Massachusetts governor Mitt Romney the sweeping victory — and the sense of inevitability — that he has sought for so long.

Or, if Romney loses key states to the bargain-basement campaign of rival Rick Santorum, Tuesday might be the political equivalent of a groundhog seeing his shadow.”

Results have already begun filtering in just as Crikey hits deadline, so we’ll update all voting news as it comes in. Here’s a look at the 10 Super Tuesday states.

4.30pm update: Mitt Romney has won Ohio, according to latest updates from CNN and Politico. 

2.30pm update: North Dakota has just been called for Santorum. Still not vote results from Alaska, but only Ohio and Idaho remain in doubt now (although Idaho seems an easy win for Romney). Just to clarify:

Romney has won: Massachusetts, Virginia and Vermont

Santorum has won: North Dakota, Oklahoma, Tennessee

Gingrich has won: Georgia.

In total Romney now has 288 delegates, Santorum has 121, Gingrich has 72 and Paul has 31.

1.30pm update: Santorum has won Oklahoma and Tennessee, Ohio remains tight (although Santorum has slipped slightly ahead).

Ohio

Results in: It’s been a neck and neck race but it seems Romney has just got over the line and won.

Ohio is one of the key battlegrounds reports Paul Steinhauser for CNN:

“Ohio, because of its status as a crucial battleground state in the general election, is getting the most traffic on the ground and on the airwaves from Romney and his chief rival, former Sen. Rick Santorum.  A CNN/ORC International poll released Monday indicates that Ohio is a dead heat between Romney and Santorum, with each grabbing 32% of likely GOP primary voters. Former House Speaker Newt Gingrich was at 14% and Rep. Ron Paul of Texas was at 11%.

… “When it comes to the air war, Super Tuesday is really Super Ohio. Although ads are running in Tennessee and Georgia, more attention is being paid to Ohio,” said Kenneth Goldstein, CNN’s consultant on TV advertising and president of Campaign Media Analysis Group, a company that tracks and estimates the costs of campaign ads running on the air.”

Tennessee

Results in: Santorum won Tennessee with 39% of the vote, Romney got 28%. So far 33% of the vote has been counted.

Patrik Jonsson in Christian Science Monitor explains why Tennessee is a key state:

“On Super Tuesday … the three-way tie between Mitt Romney, Mr. Gingrich, and Rick Santorum in Tennessee has emerged as one of the biggest symbolic contests of the Republican primary season.

A win for Mr. Romney in a bona fide Southern state could mean he is at last making inroads with the evangelical Christian and hard-right voters who’ve so far held at arm’s length the former governor of the liberal bastion of Massachusetts.”

Massachusetts

Results in: Romney has just been declared the winner. He was expected to romp it in and early results give him over 70% of votes.

As Ben Jacobs reports in Daily Beast:

“Boston-based Republican strategist Lenny Alcivar says Massachusetts is one of ‘the few states in this election season that’s actually going to follow conventional wisdom.’ Romney — who has lived in the state for 40 years, as governor for four of them, and has been endorsed by every Republican state legislator but one –will win.”

Oklahoma

Results in: Oklahoma has just been called for Santorum, with 35% of the vote compared to Romney’s 27%.

A crucial state, given every winner of the Oklahoma Republican primary since they began in 1988 has become the party’s nominee. According to the NY Times, the likely winner is Santorum.

“Voters lined up early Tuesday to cast primary ballots in Oklahoma, where Rick Santorum was hoping his particular brand of social conservatism and flurry of late campaigning would help him beat his Republican rivals in the state considered ‘the reddest of the red’,” reports Oklahoma newspaper NewsOK.

Alaska

It’s likely the delegates will be split relatively evenly between the four nominees. As the Alaska Dispatch explains:

“In years past, Alaska’s small population has prompted candidates to spend campaign funds and time elsewhere. But this year, with unlimited donations filling coffers and a still-close primary race, the leader [Romney] has on multiple occasions sent family surrogates to campaign, the dark horse doctor [Ron Paul] has actually made the trek north, and the two in between have played up Alaska talk radio and phone-in town halls … A time-tested theorem in Alaska politics: party kowtowing matters less here than perseverance, independence and a willingness to do what’s right for Alaskans. Mavericks, write-ins and sometimes renegades win here on Election Day.”

Idaho

Results in: An easy win for Romney with 69% of the vote.

Romney seems a clear winner, likely to get all the state’s delegates. A fairly forgotten state and there’s been barely any polling of it, although it is traditionally Republican. This is the first time Idaho’s primary has been held on Super Tuesday.

North Dakota

Results in: Santorum has won with 40% of the vote. Ron Paul came second with 26%.

North Dakota has 28 delegates and results are expected to be split among the nominees, with more for Romney and Paul. However, in North Dakota the results are not binding and therefore delegates are not forced to cast ballots at the National Convention that reflect caucus-goers’ support.

Vermont

Results in: Romney won around 39% of the vote according to early results, with Paul at 26% and Santorum at 23%.

Ben Jacobs explains the importance of Vermont in the Daily Beast:

“While just 17 delegates are at stake in Vermont, the Romney camp has paid staff working there, and has organised trips of volunteers from New Hampshire and a surrogate visit from John Sununu, the former governor of the Granite State. The Paul campaign also has staff on the ground in the Green Mountain State and it is one of the few states where Paul is airing television ads — and is actually outspending Romney on the airwaves there.”

Virginia

Results in: Romney wins 59% of the vote at the current count.

Romney was expected to coast easily to victory, with 43 delegates out of a possible 46. Santorum and Gingrich are not on the ballot in Virginia because they failed to get enough signatures to qualify.

Georgia:

Results in: Gingrich remains Georgia’s Peach and won his home state. He got 48% of the vote, with Santorum grabbing 22% and Romney 22%.

Polls indicated Gingrich would win the Peach State, but Romney is a close second and 39% of voters think Romney’s a better chance of beating Obama (compared to 30% supporting Gingrich). This video of Gingrich taking an on-camera nap shows just how exhausting a presidential campaign can be.

For wonks following along at home, The New York Times, Politico and CNNall have good live coverage. Meanwhile, the US president criticised the Republican candidates on Super Tuesday, noting that they appeared too casual in discussing the possibility of military action against Iran.

“Now, what is said on the campaign trail, you know, those folks don’t have a lot of responsibilities,” said Obama. “They are not commander-in-chief. And when I see the casualness with which some of these folks talk about war, I’m reminded of the costs involved in war. I’m reminded that the decision that I have to make, in terms of sending our young men and women into battle, and the impact that has on their lives, the impact it has on our national security, the impact it has on our economy. This is not a game, and there is nothing casual about it.”