Bizuayehu Tesfaye, Associated Press
Mitt Romney

In 2008, John McCain got his knockout blow on Super Tuesday. Mitt Romney can expect no such luck this time around. The game has changed a lot in four years, and Super Tuesday ain’t what it used to be.

A total of 21 states put it all on the line that 2008 day, with most delegates going either in statewide winner-take-all or congressional district winner-take-all. This year, only 10 states are on the line, and most of the delegates will be divided proportionally.

Like an army fighting the last war, the GOP after 2008 flipped from emphasizing an early winner, which allowed the party to regroup and take on the Democrats. That winner-take-all format tended to favor the leader and created a more decisive outcome. Republican elites felt the early winner approach in 2008 picked the wrong guy, and the party opted for a more deliberate and drawn-out contest this year. They got it.

William Galston at the New Republic noted that it's not just the number of states and the rules, but also the mix of states that muddles things for this year's Super Tuesday:

"In 2008, Mitt Romney didn’t win a single primary in the Deep South, and almost half his victories came in states that share a border with Canada. With that track record, he’s not likely to prevail in Georgia or Tennessee or Oklahoma on Tuesday, though he should win comfortable victories in Massachusetts and Vermont. And because neither Newt Gingrich nor Rick Santorum managed to get on the Virginia ballot, Romney should prevail there as well, barring a shocking last-minute surge in support for Ron Paul."

Romney's success on Saturday in Washington's caucuses was sufficiently reassuring to prompt two key endorsements over the weekend, adding to his momentum heading into Tuesday.

Eric Cantor, a prominent GOP House leader from Virginia, endorsed Romney on Sunday. Romney adviser Eric Fehrnstrom speculated that Cantor was looking to protect his House majority, fearing a down-ticket debacle with Santorum at the head, the Washington Post reported.

“Republicans want coat tails, not concrete shoes,” Fehrnstrom said. “Rick Santorum is a concrete shoe for Republicans who are running for the Senate or for the House ... He didn’t say it, but I’ve got to believe that in the back of Eric Cantor’s mind is maintaining the Republican majority in the House. I think it’s easier to do that with Mitt Romney at the top of the ticket as our strongest possible jobs candidate."

Joining Cantor in endorsing Romney was deficit-hawk Sen. Tom Coburn of Oklahoma. Popularly known as "Dr. No" because he refuses to compromise on fiscal disipline, Coburn's endorsement should carry weight with the tea party crowd, but may have little impact at home, as Oklahoma appears to be Santorum's strongest ground on Tuesday.

Cantor's Virginia is also on the menu, but both Gingrich and Santorum failed to make the ballot there, and Romney is a lock to win the state against Ron Paul.

Santorum's organizational problems in Virginia are echoed in Ohio, where he failed to get delegate slates submitted in several congressional districts. The consequence is that even a narrow win for Santorum here could result in more delegates tipping to Romney.

Still, Ohio remains the rhetorical prize of the day. A narrow win or loss here offers huge bragging rights, as Romney struggles to prove that Michigan was no fluke and he can win the Midwest. Polls over the weekend show Santorum and Romney neck and neck in the Buckeye state.

The largest prize of the day is Georgia, with 76 delegates, but proportionality will weaken Gingrich's take, probably cutting it nearly in half.

For data hounds, Nate Silver's New York Times FiveThirtyEight blog is the best place to get a pre-election numbers fix. The math is complicated, as most states award delegates based on some combination of statewide proportionality and congressional district wins.

After a careful analysis, Silver projects "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."

Eric Schulzke writes on national politics for the Deseret News. He can be contacted at [email protected].