(CBS News) -- Voters in ten states participate in primaries and caucuses on Tuesday for contests that will award more delegates in the fight for the Republican presidential nomination than all the previous contests combined. And while no candidate is expected to deliver a knockout blow, the outcome will dramatically reshape the contours of the race.
All ten states holding contests Tuesday are awarding delegates proportionately - allocating them based on the outcome in congressional districts, a candidate's percentage of the statewide vote, or a combination of the two (as in the case of Ohio). The lack of "winner take all" contests makes it almost impossible for the remaining GOP presidential hopefuls to accrue enough of the 419 delegates at stake Tuesday to create an aura of true inevitability around their candidacy.
Still, it's likely that Mitt Romney will emerge from Super Tuesday with momentum. There are four states where he is almost sure to claim victory: Massachusetts, Vermont, Idaho and Virginia. Romney has a home state advantage in Massachusetts, where he served as governor, and his style and background make him a natural fit in the Bay State as well as in neighboring Vermont. A combined 55 delegates are up for grabs in the two states, and Romney is expected to claim most of them.
Idaho has the highest concentration of Mormons of any state outside of Utah, and they are expected to put Romney over the top in the state's caucuses. Virginia, meanwhile, would likely have been a hard-fought state had Newt Gingrich and Rick Santorum managed to get on the ballot; because they did not, the state has been left to Romney and Ron Paul, with polls suggesting Romney will win the vast majority of the state's 46 delegates.
Romney will also win delegates in the swing state of Ohio, which is holding the most closely-watched of Tuesday's contests. Polls showed Romney and Santorum in a close race for the state going into Election Day, and whoever wins will be able to claim significant momentum. For Romney, a victory would help put to rest doubts that he can win over the working-class, Midwestern voters he would need to attract in a potential general election campaign; for Santorum, a win boost his argument that he could win in November and reinforce the notion that he is the only viable conservative alternative to Romney in the race.
Even if he wins the state, however, Santorum is unlikely to take the majority of its delegates. That's because Santorum, who long ran a shoestring campaign lacking the organizational and financial resources of his rivals, did not do the necessary legwork to be eligible for more than one quarter of the state's 66 total delegates up for grabs. The Romney campaign has pointed to that fact (and to Santorum's failure to get on the Virginia ballot) to argue that Santorum lacks the organizational chops to compete with President Obama; if Santorum wins the state, expect the Romney camp to point to the delegate situation to counter Santorum's claim of renewed momentum.
Also on the calendar Tuesday is a trio of Southern states: Georgia, Tennessee and Oklahoma. Georgia is the state Gingrich represented in Congress, and polls show him with a strong lead there; the state offers 76 delegates, more than any other Super Tuesday contest. Gingrich is also making a play in Tennessee, campaigning and running ads in the state in the wake of a new poll that showed him in a three-way tie - though another new survey showed Gingrich down 15 points to Santorum in the state.
Gingrich's strategy for a comeback is to win Georgia, possibly take Tennessee and then build on his southern state momentum to score wins next week in Mississippi and Alabama. But it's a tall order. Unless Gingrich can pull out Tennessee, it will be hard for him to keep making the case that he belongs in the race - particularly with Santorum making the point that if conservatives could finally unite around a single candidate, that candidate would have a good chance to beat Romney. Of course, Gingrich could still defy the calls to exit the race if things don't go well Tuesday - particularly if Las Vegas casino mogul Sheldon Adelson keeps pouring millions of dollars into the super PAC backing his campaign.
Polls show Santorum the strong favorite to win Oklahoma and a good chunk of its 43 delegates, though Romney has a tiny chance to score an upset victory. Tennessee, meanwhile, could go either way: Polls show Romney surging to within striking distance of Santorum there, and Romney could end up with a plurality of the state's 58 delegates. A victory for Romney in Tennessee would go a long way toward counteracting the conventional wisdom that the Ivy League-educated governor of a Northeast state cannot win over Southern voters.
If Romney can win both Tennessee and Ohio - and avoid any upsets - he'll have a strong argument that he is a viable national candidate, and a GOP establishment fearful of the negative impact of a long primary fight will likely follow House Majority Leader Eric Cantor's lead and line up behind him. If Santorum wins the two states, meanwhile, it will likely extend the race and renew talk of a contested nominating convention in Tampa in late August.
There are two other states holding contests on Tuesday, both caucuses: North Dakota, where 28 delegates are at stake, and Alaska, where 24 delegates are up for grabs. Paul has been focused on both states (along with the third caucus state, Idaho) as part of his strategy to build up delegates by focusing on low-turnout caucus contests, where Paul's passionate supporters can have the most impact. North Dakota and Alaska offer Paul's best chance to finally win a state, though there has not been polling in either state.
Entering Super Tuesday, CBS News estimates that Romney leads the pack with 187 delegates, with Santorum in second with 65 delegates; Gingrich follows with 30, and Paul with 20. Even if Romney wins a majority of the 419 delegates available on Tuesday - which is well within the realm of possibility - he will not approach the 1,144 delegates needed to claim the nomination.
Still, he could certainly emerge from Super Tuesday with an aura of inevitability that has thus far eluded him. The latest Gallup tracking poll shows Romney leading Santorum by 16 percentage points nationwide; if Santorum fails to generate positive headlines on Tuesday, it's hard to see how he closes that gap, though Gingrich leaving the race would certainly help. Indeed, Romney would love to see Gingrich best Santorum in Tennessee, providing a justification for the former House speaker to stay in the race.
No matter what happens, it's important to remember that Romney has a major advantage over his rivals: A financial edge that has allowed the candidate and the super PAC backing him to significantly outspend them in advertizing. He also has better organization than any of the other candidates and more support from the party establishment. A big night for Santorum would give him a boost in donations, but it won't change that disparity. What it would do is throw a race that seems to be breaking for Romney back into chaos - and keep establishment Republicans fretting that the longer the primary fight goes, the longer their odds get for winning in November.