Ohio Primary: Among Super Tuesday's 10 Contests, One Crucial Test Justin Sullivan / Getty Images Supporters of Republican presidential candidate Mitt Romney look on during a campaign rally at American Posts on Feb. 29, 2012 in Toledo, Ohio. With 66 delegates at stake, Ohio is not the largest target on Super Tuesday, which will see 10 contests held on March 6. But it is the most important. There are no demographic or regional arguments to explain away a loss for Mitt Romney - no home-state advantages, no failures to reach the ballot. Its role in the general election gives Ohio symbolic weight with Republicans, and its Rust Belt-electorate will test the key lingering questions of the GOP primary: Can Rick Santorum build a coalition to defeat Romney outright in a major primary state, and is Romney really ready for a general-election fight with Barack Obama? "Not only is Ohio demographically representative of the country at large, reflecting virtually every important group except Latinos," writes Ohio State political science professor Paul Beck, "it also combines a tradition of moderate Republicanism and recent Tea Party support." MORE: Campaign 2012, Where Old Media Is New Again Ohio Republicans populate two key areas: big-city suburbs, especially outside Cincinnati, and rural hamlets scattered across the southern stretch of the state. Romney won Michigan on the strength of his performance in Oakland County, outside Detroit, while Santorum failed to run up high enough margins of victory in conservative rural areas. In terms of culture and demographics, Ohio is similar, and the turnout of the state's Evangelical social conservatives could be decisive. A week out, polling showed Santorum pulling it off: he leads Romney by high single-digits or low double-digits, and his supporters say they're more settled on their vote than Romney's. The time frame for a turnaround is short. Romney overcame similar deficits in Michigan, but he had several weeks to do it. One potential upside for Romney is his money advantage, which enabled him to pour resources into Ohio while Santorum was stretching to keep Romney from doubling or tripling his investment in Michigan. Adding to Ohio's meaning is the fact that the other nine contests on Super Tuesday are likely to splinter between the candidates, offering few surprises. PHOTOS: The Final Sprint in Michigan and Arizona The western caucuses could go almost any way. Romney won North Dakota and Alaska four years ago and has captured endorsements from governor Butch Otter and Senator Jim Risch in Mormon-rich Idaho. But the activist-heavy format is less suited to his campaign this time around, especially when he hasn't had the chance to exploit his fundraising advantage through organizing. Romney's strengths are easy to spot: they're in states on his home turf in the Northeast-and one where his primary foils are not on the ballot. He's a shoo-in in his old gubernatorial stomping grounds of Massachusetts, which will assign 41 delegates proportionally. The same is likely true in Vermont, where Romney has a shot at all 17 delegates if he can clear 50% of the vote. Virginia, which will send 49 delegates to the convention and is an important general-election state, could have been a prime Super Tuesday battleground. But thanks to their campaigns" organizational deficits, neither Santorum nor Newt Gingrich made the ballot there, making it a Romney lay-up. PHOTOS: Political Pictures of the Week, Feb. 18-24 Meanwhile, Romney is vulnerable in the South.South Carolina handed him his first major defeat of 2012, and polling across the region has consistently showed him trailing a variety of comers for months. Scant polling in Tennessee (58 delegates), where early voting ended Tuesday, shows Santorum with a huge lead. Despite his collapsing numbers everywhere else, Newt Gingrich has retained a solid lead in Georgia, which will send 76 delegates to Tampa; even if Gingrich falters, Santorum is running second. There hasn't been much polling in Oklahoma (which is not really the traditional South, but similarly conservative and voting on Tuesday), but Santorum leads by close to 20 points in the few surveys conducted. Its 43 delegates will be doled out proportionally, and with Gingrich in second, Romney doesn't look likely to get much out of it. Super Tuesday won't end Romney's Southern troubles either: Alabama, Mississippi and Louisiana all vote later in March. Assuming its redistricting situation gets sorted out, Texas" huge cache of 155 delegates could complicate the race if it runs late into spring. But whether the primary campaign actually lasts that long may hinge on Ohio. MORE: Election 2012: Can Anyone Stop Romney?