Raleigh, N.C. — With limited time until Election Day, the campaigns of President Barack Obama and Republican challenger Mitt Romney must decide where to focus.

Various polls show a toss-up in North Carolina, but most political analysts give Romney the edge. Obama's campaign is trying to make a move in the state over the next few days with a last-ditch barrage of high-powered appearances.

Vice President Joe Biden's wife spoke Friday in Asheville and outside Charlotte, former President Bill Clinton will be in Raleigh on Sunday and first lady Michelle Obama makes her third trip to North Carolina in recent weeks with a Monday speech in Charlotte.

"They're not coming here because it's a beautiful place and the weather is nice this time of year. They're coming here because the Obama campaign thinks they have a chance to win North Carolina," Democratic political consultant Gary Pearce said. "I think the last few days are critical in North Carolina and everywhere. It's that close a race."

Obama's political grassroots effort boasts a bigger, more organized operation than in 2008. From a Fuquay-Varina phone bank to a volunteer staging location in north Raleigh, the campaign claims it knocked on 50,000 doors on Thursday alone.

"Success is making sure we contact voters. It's all about voter contact," campaign volunteer Hanna Lyons said.

Learning from Republican John McCain's loss in 2008, the Romney campaign stepped up its own ground game. It is having volunteers call and knock on doors in hopes of making North Carolina a red state again.

"(We've increased) everything from the number of volunteers who are out there willing to give of their time and walk the streets to the number of yard signs you see supporting the ticket this time around," campaign volunteer Pearce Godwin said.

Republican political consultant Carter Wrenn said that, with unaffiliated voters breaking for Romney in North Carolina, the president's in trouble.

"It just doesn't look close here to me," Wrenn said. "You'd expect they'd be focusing on a state that's somewhat closer, but maybe they know something we don't."