(CBS News) As the final weekend of campaign 2012 draws to a close, the race for the White House could not be closer. The latest polls indicate a virtual tie.
Taking no chances, the candidates are crisscrossing swing states.
CBS News correspondent Nancy Cordes reports President Obama joined forces this final weekend with his most powerful supporter -- former President Bill Clinton -- who took on Romney with relish.
"He has tied himself on so many knots trying to say he didn't oppose what he clearly opposed that I expected today he will be offered a job as a chief contortionist at Cirque du Soleil!" Clinton joked to a crowd in New Hampshire.
Mr. Clinton is being dispatched to four cities in Pennsylvania Monday to blunt a last-minute offensive by the Romney camp in that typically blue state. Mr. Obama brings up the Clinton years at every rally.
Complete coverage: The Battlegrounds
"We tried our ideas and they worked: The Middle class grew, Americans prospered, deficits became surpluses. We tried their ideas: Incomes went down, deficits blew up, massive financial crisis we are still cleaning up," the president told a campaign rally.
Obama officials revealed this weekend that campaign workers have registered 1.8 million new voters in battleground states -- double the number they registered before the 2008 election.
President Obama will spend the last day of his last campaign in three Midwest states Monday: Ohio, Wisconsin and Iowa. He said Sunday that at this stage in the race he is merely a "prop," and that the real stars of this drama now are his get out the vote team and the voters themselves.
CBS News correspondent Jan Crawford reports Republican presidential candidate Mitt Romney spent Sunday in the Democratic stronghold of Pennsylvania. With polls showing the race has tightened there, the Romney campaign decided to give it a shot.
"Two more days, and we can get to work rebuilding our country," Romney told the crowd.
In the crucial state of Ohio earlier Sunday, Romney talked in sweeping language about a brighter future.
"Two more days we start rebuilding our country and restoring our confidence and renewing our conviction. Confidence that we're on a solid path to steady improvement. American's don't settle. We build, we inspire, we dream, we achieve!" Romney said.
More than 20,000 people waited hours to see Romney in Pennsylvania, and if he could take this state, it would give him more flexibility. But Pennsylvania has been a tough one for Republicans--George H.W. Bush is the last president to win it, in 1988.