Updated

President Obama and Bill Clinton will campaign together Monday, opening the final full week before Election Day with a three-state battleground blitz.

The joint rallies underscore Clinton's role as perhaps Obama's most important surrogate in the tightly contested White House race with Republican Mitt Romney. In campaign events, television advertisements and a well-regarded speech at the Democratic convention, the former president has been a chief defender of Obama's economic record, winning praise for sometimes explaining that record better than Obama himself.

The two will headline rallies Monday in Orlando, Fla., Youngstown, Ohio, and Prince William County, Va. It's the first time Obama and Clinton will campaign together during this election, though they have shared the stage at fundraisers and appeared together briefly at the party convention.

The three states are among the biggest electoral prizes up for grabs in the Nov. 6 election. Polls show Obama has an edge in Ohio, but Romney has whittled away the president's earlier leads in Florida and Virginia.

For Obama and Clinton, the rallies serve as another benchmark in a year that has solidified their transition from political rivals to allies.

Following his convention speech, Clinton has made a series of solo appearances on Obama's behalf. A high-profile event in Ohio last week also featured Bruce Springsteen.

Clinton has also appeared in campaign ads, including one out this week where the former president argues that Obama "got it right" with his economic agenda. And he's helped both Obama's campaign and the main super political action committee supporting him raise money.

Obama advisers are banking that Clinton's presence on the campaign trail will shore up the Democratic base. And they hope undecided voters will draw a connection between Obama's policies and the ones Clinton pushed when he presided over a thriving economy.