With the race in a dead heat nationally, both candidates touched down briefly in Dubuque, a Mississippi River city of 58 000 people, as they sprinted across the country in a bid to secure any possible advantage before Election Day.
In an airport rally early in the afternoon, Romney urged supporters to try to sway friends and neighbours who back Obama. He said he would reach out to Democrats as well if elected — a stance that could appeal to independent voters who have little stomach for partisan gridlock.
"I want you to reach across the street to the neighbour, who has that other sign in his front yard. And I'm going to reach across the aisle in Washington, DC, to the politicians who are working for the other candidate," Romney told about 2 000 people.
Six hours later, Obama reminded about 5 000 people in a park in downtown Dubuque that he had started his first presidential bid in Iowa in 2007, and highlighted successes of his time in office, such as ending the war in Iraq and expanding access to healthcare.
"After two years of campaigning and after four years as president, you know me by now. You may not agree with every decision I made, you may have sometimes been frustrated with the pace of change. But you know that I say what I mean and I mean what I say," Obama said.
A new poll by the Des Moines Register newspaper showed Obama leading Romney by 47% to 42% in Iowa, though the survey showed the president barely edging his opponent on the critical question of which candidate would do better fixing the economy.
Earlier in the day in Ohio, Obama hammered Romney for opposing his bailout of the auto industry and said his challenger tried to scare workers by saying inaccurately that Chrysler planned to shift jobs to China.
About one in eight Ohio jobs is tied to auto manufacturing, and the bailout has helped Obama win over some of the white working-class voters who are heavily backing Romney in rest of the country.
"I've been a Republican for 35 years and I've never voted for a Democrat on the federal level — until now," retiree Patrick Dorsey said as he waited for Obama to speak. "Economically, Romney's just going to make the rich richer."
Romney will have a hard time winning the White House if he does not carry Ohio, and a Reuters/Ipsos poll released on Saturday showed him trailing Obama by a statistically meaningless margin of one percentage point in the state. Other polls show him trailing by a larger margin in Ohio.
The race for the White House remains effectively tied at a national level, with 47% backing Obama and 46% supporting Romney, according to a Reuters/Ipsos daily tracking poll released on Saturday.
Still, analysts say Obama holds an edge in many of the eight or nine competitive states that will determine who controls the White House. Reuters/Ipsos polls released on Saturday showed Obama leading by three percentage points in Virginia but trailing by two points in Colorado. The two were dead even in Florida. All the results were within the credibility interval, a measurement of the accuracy of online polls.
Romney has tried to expand the battlefield over the past week to states that had been considered beyond his reach.
Obama officials say the Romney campaign is visiting those states out of desperation because he has been unable to establish a clear lead in other battleground states.
Capping Saturday's tour , Obama made a joint appearance with Clinton before an enthusiastic crowd of 24 000 — one of the largest of his campaign — at an outdoor arena in Bristow, Virginia. The Dave Matthews Band provided the warm-up act.
On stage, Clinton mocked Romney for his shifting positions and attempts to explain away earlier comments on the auto bailout, saying the Republican "tied himself in so many knots … that he could be hired as the chief contortionist for the Cirque du Soleil."
Clinton, seen by Obama's campaign as appealing to undecided voters because of the prosperous economy he presided over, lauded the president as a "good commander-in-chief and a good decider-in-chief."
Earlier on Saturday, Obama also held a rally in Wisconsin, a state considered safely in his column earlier this year.
"You don't take anything for granted, you go as hard as you can to the end, and that's exactly what we're going to do in all our battleground states," said campaign manager Jim Messina.
Obama started the day at the federal government's disaster-relief headquarters in Washington, where he received an update on the efforts to help north-eastern coastal states recover from devastating storm Sandy.
The storm has afforded the Democrat an opportunity to rise above the fray of campaigning. But it has also raised the stakes for him to show his administration can respond quickly and effectively in a crisis, as residents of New York and New Jersey vent frustration at power outages and gasoline shortages. – Reuters