Jim McTague of Barron’s outlines potential election scenarios tied to this week’s Super Tuesday primary elections:

Most political experts are predicting a narrow Super Tuesday victory by Romney that won’t shake Santorum from his tail but may leave Gingrich and Paul eating serious amounts of dust.

Larry Sabato, director of the University of Virginia’s Center for Politics, says Romney’s only real advantage is that he’s on the ballot in Virginia, and Gingrich is not. Subtract Virginia, where he expects Romney to win, and Super Tuesday will essentially be a draw, he says.

Scott Rasmussen, a pollster out of Asbury Park, N.J., says that a national poll he conducted last week showed Santorum’s star power is fading, albeit slightly. This means that Romney will be stronger in states like Ohio, where he was polling miserably just a few weeks ago. “I don’t know if this says he will win, but the polls are moving in the right direction for him,” says Rasmussen.

“The real unknown is what’s going to happen to Newt Gingrich supporters,” says Rasmussen. If they were to conclude that Rick Santorum is their most realistic option, then Santorum could win in Georgia, Tennessee and Oklahoma, he says. But that would require everything breaking just right for the Pennsylvanian. Rasmussen says the most likely outcome is a mixed result, with Romney becoming even more entrenched as the front-runner, but Santorum remaining within striking distance.

If that’s the case, then the battle won’t be decided until the Texas primary in late May, by which point GOP candidates and their coffers will be depleted. Advantage: Obama.