I’m as guilty as anyone of placing the most importance on Ohio among today’s primaries, but it should be remembered that, from a delegate point of view, Ohio doesn’t really matter. Today’s contests are all proportional to some degree. A handful of states (Ohio, Vermont, and Virginia) are winner-take-all by congressional district, with some at-large delegates doled out proportionately. Santorum didn’t qualify for delegates in all of Ohio’s congressional districts, so he’s likely to lose the delegate battle even if he wins the popular vote. Romney and Ron Paul are the only candidates on the ballot in Virginia and write-in votes are not allowed, so Romney will win almost all the delegates there because he will win in every congressional district. Vermont only has one congressional district, and Romney will win the popular vote and therefore all the CD delegates.
In the states Romney is likely to lose, he will still win a fraction of the delegates. The real question is whether Romney will win more than 50% of the delegates today or he won’t. My guess is that he will. So, from a technical standpoint, Romney will probably improve his position tonight even if he loses Ohio’s popular vote.
So, why is Ohio so important? Mainly because it’s the best chance for Santorum to prove that he can actually beat Romney. It’s also Romney’s best chance to exceed expectations. No one is going to give Romney credit for winning his home state of Massachusetts or for winning in tiny Vermont or for winning in Virginia in a one-on-one contest with Ron Paul. He needs to win somewhere else to impress. If Santorum can carry Tennessee and Oklahoma, that will be nice and provide him with an excuse to keep going, but blowing a big lead in Ohio will be the main message people take away.
A good night for Romney will be if he can win Ohio, Virginian, Massachusetts, and Vermont. A great night will be if he can also win in Tennessee and come in second behind Gingrich in Georgia. A bad night will be if he comes in third in Georgia and loses in Ohio and Tennessee.
If Romney has a good or great night, we’ll probably see the electorate start to rally around him. But if he has a bad night, the contest will continue in its present form, and move to Alabama and Mississippi and Missouri with Romney looking to take a beating.
Ohio and, to a lesser degree, Tennessee are the keys tonight. If Romney falls short, the Republicans may simply give up on the idea of winning the presidency.