Tennessee could heighten the Ohio effect. If either candidate wins both Ohio and Tennessee, everything said in the previous paragraph will be even more true. A double victory by Romney will decisively end Santorum’s quest. If  Santorum  won both states, Romney would have a lot of explaining to do.  If the states split, Ohio matters more.

The other thing to watch tonight is the battle for seats on the 66-member Ohio Republican Central Committee. You never thought it would be worth your while to watch state central committee races? Jessica Alaimo of the Marion Star was right earlier this week in asserting that these contests have “drama” and are worth paying attention to. This is a grudge match between the state Republican Chairman Kevin DeWine and Gov. John Kasich. Kasich wants to replace DeWine as party chair. DeWine wants to hold his job. The two men have taken their fight directly to the Republican electorate and put up competing slates of candidates for central committee seats. If the DeWine slates prevail, it would be a blow to Kasich. But the races also have national implications because Kasich in some districts has allied with the Tea Party. A defeat for Tea Party slates would be a sign that the movement is weakening in one of the most politically important states in the nation. Neutral sources I spoke with in Ohio last week thought DeWine’s forces had the advantage.

In the presidential race, the momentum has been with Romney and I think it should be enough to push him over the top. He and his Super PAC also enjoyed a huge spending advantage over Santorum. (These are the reasons why I predicted an Ohio win for Romney in PostPartisan’s pundit sweepstakes). But I confess to a nagging doubt. Santorum did appear from some polls to have the advantage among those who cast ballots early, and I wonder if Santorum forces have more energy and commitment than Romney’s voters do. But that’s why we decide these things with elections and not predictions.