Heading into Tuesday's Republican presidential primary in the swing state of Wisconsin, Mitt Romney has a seven-point polling lead over Rick Santorum, and New York Times numbers guru Nate Silver gives Mitt an 88 percent chance of pocketing the Badger State's 42 delegates. Romney is also widely expected to dominate Tuesday's other contests in Maryland and the District of Columbia, all but assuring that he'll end the day more than halfway to the 1,144 delegates he needs to officially nail the nomination. Can Romney finally erase doubts that he'll be the GOP's pick to challenge President Obama this fall?

The Badger State may be decisive: Wisconsin "could be the tipping point," GOP operative Todd Domke tells the Boston Herald. In recent days, Romney piled up endorsements from former President George H.W. Bush, GOP budget chief Paul Ryan, and Tea Party hero Sen. Marco Rubio. Now, if Romney triumphs in yet another critical swing state, he'll have "momentum that's undeniable."
"Primaries may put Romney over the top"

And Romney is on a roll: Santorum is still "waging a tenacious battle," bluntly telling voters that the GOP needs a more conservative candidate than Romney, say Jeff Zeleny and Jim Rutenberg in The New York Times. However, if Romney takes Wisconsin, he'll be kicking off what's likely to be a month-long "series of wins" in Mitt-friendly, delegate-rich states, including New York. Those April contests will only boost Romney's "commanding" delegate lead, and seal the nomination in the eyes of GOP leaders. Party bosses are "increasingly eager to take on President Obama," and they're ready to rally around Romney.
"In Wisconsin, Romney nears the tipping point"

But don't expect Santorum to quit: "April and May are virgin territory for the Republicans," says Ken Rudin at NPR. Normally, the nominating race is decided shortly after Super Tuesday. "But as long as Santorum's disdain for Romney continues, as long as he keeps on winning states, and as long as there continues to be doubts about Romney's core principles — the 'Etch a Sketch' comment by his top aide didn't help — there's no sign this will end any time soon."
"Santorum's win in Louisiana puts off discussion about uniting behind Romney"