Later Thursday, in his hometown of Chicago, Obama was scheduled to be the first president to vote early in person. By making a special trip just to cast his vote, Obama sought to build awareness about the early voting option, which is a vital part of both campaigns' political operations.
The nonstop travels were the busiest single stretch of Obama's long and combative run for a second term.
Romney was waking up in Cincinnati to kick off a daylong swing through three Ohio towns, sharpening his focus on a state that's critical to his hopes of winning the White House. The Republican's advisers say their internal data has him tied to win the state's 18 electoral college votes, but public polling has shown Obama with a slim lead.
Romney is working to cast Obama's campaign as focused on small issues while the Republican ticket is focused on fixing the nation's serious fiscal problems.
"His campaign seems to be smaller and smaller by the day," Romney told more than 2,000 people in an airplane hangar off the tarmac in Cedar Rapids, Iowa, his campaign plane looming behind him. "Attacking me is not an agenda for the future."
He campaigned in Iowa hours after Obama, who had stopped in the state earlier in the day.
Romney's stop was brief; less than an hour after landing Romney was en route to Cincinnati, Ohio, where he spent the night.