Both the candidates and the media will have a hard time pegging who’s up and who’s down in the Super Tuesday states. We know from past polling that a victory by one candidate one week can send his numbers skyrocketing, making polls irrelevant. Moreover, big election wins and/or gaffes take a while to settle in as voters mull the new terrain. In short, current polling isn’t much help since virtually all of it reflects the state of the race before Tuesday’s contests.

We can look at national polling, since the race is now about not one race but 10 on Super Tuesday. There we see Mitt Romney is getting a lift, with his lead over Rick Santorum up to eight points. But Newt Gingrich is also rising, now back up to 16 points. (It may be that wary Santorum voters are sliding back to Gingrich’s column.) If that bump is real, Gingrich may drain off critical votes from Santorum in Georgia, Tennessee and even Oklahoma.

In Ohio, Santorum’s big pre-Feb. 28 leadis likely to shrink. Romney was there yesterday and, after a swing through Idaho, Washington and North Dakota, he will head back. Santorum was in Tennessee yesterday and today is slated to be in Washington (its race is on Saturday), but by Friday he, too, will be back in Ohio. One of the lessons he may have picked up in Michigan is that in must-win states, time on the ground still matters. If his lead drops precipitously he would be wise to spend the weekend there.

The importance of Ohio can’t be overstated. As Karl Rove argues, “Mr. Santorum is focused on Ohio, Tuesday’s key battleground with 66 delegates. Mr. Romney can afford a narrow loss there as long as he wins a solid plurality of all the Super Tuesday delegates. Mr. Santorum’s candidacy will realistically be at an end if he loses the Buckeye State, though he could linger for weeks. Even a win leaves him on life support unless he can also best Mr. Romney in Tuesday’s Southern contests, coming in first or second with Mr. Romney trailing in second or third place.” Put simply, Ohio is Santorum’s Michigan; a loss sends him home. If he can’t make good on his promise to appeal to blue-collar, Rust Belt voters, the rationale for his candidacy evaporates.

In reality, not all 10 states are really in play on Tuesday. Only Rep. Ron Paul (R-Tex.) and Romney are on the Virginia ballot. (I’ve seen a handful of lawn signs and bumper stickers, but there is virtually no awareness here that a primary is around the corner.) Massachusetts and Georgia in all likelihood will go to the home-state candidates. Romney is the heavy favorite in Vermont and and Idaho. That leaves Ohio, Tennessee, North Dakota and Oklahoma as the most competitive contests. Watch the polls in those states and pay attention to where the candidates go. Feb. 28 was either a game-changer or simply one more twist on a winding road. But most of all, keep your eye on Ohio; that is where the race may effectively end.