ASTON, Pa. -- Mitt Romney is expected to win all five Republican presidential primaries today, but Pennsylvania and Connecticut will be watched closely for signs that he could be headed for trouble in those states in November.
A weaker-than-expected showing in Pennsylvania against Rick Santorum, who represented the state in the U.S. Senate in 1995-2007, would raise fresh questions about Romney's appeal in a general-election swing state. Pennsylvania polls show the presumptive GOP nominee within striking distance of President Barack Obama.
"What we're all looking for is, 'Will there be a sympathy vote for Santorum? A revenge vote?' " asked Terry Madonna, the director of the Center for Politics and Public Affairs at Franklin & Marshall College in Lancaster, Pa. "Romney doesn't want a four-point victory. The headline can't be about residual support for Santorum, or that Romney still has trouble with the conservative base in a state like this."
Connecticut also will offer some clues about Romney's November prospects there. The state shares a long border with Massachusetts, where Romney was the governor in 2003-07, and it has a history of embracing GOP moderates. Romney should win it big, but a very low turnout -- and lack of enthusiasm -- could signal more trouble.
Those states, as well as New York, Delaware and Rhode Island, are expected to help Romney move closer today to the 1,144 Republican National Convention delegates he needs to clinch the nomination. He has 697 delegates, according to the Associated Press tally, with 231 at stake today.
Romney campaigned Monday in Aston, a Philadelphia suburb, with Sen. Marco Rubio, R-Fla. Romney wouldn't say whether Rubio is on his list of potential running mates.
But Rubio joins a growing list of possible running mates, starting with New Jersey Gov. Chris Christie, who backed Romney as soon as he definitively decided not to run. Romney campaigned extensively with South Carolina Gov. Nikki Haley before her state's primary in January.
He also has shared the stage with South Dakota Sen. John Thune, Virginia Gov. Bob McDonnell, Wisconsin Rep. Paul Ryan, former Minnesota Gov. Tim Pawlenty, New Hampshire Sen. Kelly Ayotte, and Ohio Sen. Rob Portman.
Rubio's Cuban background, home state of Florida and rising national profile have put him at the top of many vice presidential lists. Still, some Republicans question whether he'd be better off as VP or could wait until 2016 to mount his own bid.