With Mitt Romney closing fast in Tennessee and actually pulling ahead in Ohio, it appears that 24 hours from the start of voting in the 10 states holding primaries and caucuses on Super Tuesday that Romney will take the lion's share of the delegates.

Nate Silver previews all 10 of the contests tomorrow and offers up a summary:

Adding up the projections from the ten states, I show Mr. Romney getting 217 delegates, or almost exactly half of the total available. Mr. Santorum would get 107 delegates by these projections - about a quarter of the total - with Mr. Gingrich getting 61 and Mr. Paul 25.

There is, obviously, a lot of uncertainty in these numbers -- especially since the delegate math is somewhat non-linear as when candidates fall just above or below a qualifying or majority threshold. But Mr. Romney has the makings of a strong evening, and one that could put some further distance between himself and his rivals.

Silver points out Santorum's difficulties in Ohio where he failed to get enough signatures in 6 congressional district to be eligible for the full complement of delegates if he were to win in those districts. But it is still liable to be a close race either way and a win by Santorum in Ohio will keep him alive for the foreseeable future.

Romney already holds about an 80 delegate lead over Santorum. Add a hundred to that and the task of the challengers becomes a real uphill struggle. There are fewer winner take all primaries this time around and the proportional allocation of delegates means that a close second by Romney will almost be as good as a win in most states.

Those who were counting on a brokered convention can relax.