Busy Day on Campaign Trail for Obama and Romney President Obama making an entrance at an event at Byrd Park. WORTHINGTON, Ohio - Mitt Romney adopted the mantra that fueled his opponent's victory four year ago, casting himself as the candidate of "big change" on Thursday in Ohio as he began to outline a closing argument in the state that could decide the race. On the same day, President Obama wrapped up a sleep-deprived two-day, eight-state jaunt by pressing supporters to exploit early voting in swing states as a bulwark against the possibility of a surge by Mr. Romney, traveling to Illinois to cast his own ballot 12 days before Election Day. It was a day of deeply contrasting messages that hinted at the moods and strategies inside both campaigns: Mr. Romney sought to keep projecting the air of a winner, focused on an ambitious agenda of reform, while Mr. Obama emphasized the gritty mechanics of shoring up his electoral turnout. Mr. Romney, who is essentially deadlocked with Obama in many national polls and has narrowed the president's advantage in some swing-state polls, started a three-city bus tour here by borrowing a message of change long identified with Mr. Obama's 2008 campaign. The Republican candidate promised to "tackle the problems politicians have spoken about for years but haven't been willing to deal with." "It's time for a big change, and Paul Ryan and I represent a big change for America," Mr. Romney said after rolling into an afternoon rally here. For Mr. Obama, reclaiming the change mantle as an incumbent has been one of his singular challenges. It is hard to run against Washington while traveling with an armed entourage and a big blue and white government plane. So the president has alternated between blaming Republicans in Congress for blocking change and arguing that the change Mr. Romney represents is actually more of the same policies from the Bush era. At an Obama rally in Richmond, Va., on Thursday, Senator Mark R. Warner, a Democrat, summarized the argument in pithy form. "In 2008, we changed the guard," he told a crowd of 15,000 who turned out to see the president. In 2012, we guard the change. Mr. Obama made the case, as he does most days, that change has been slower than anyone might wish but that it is under way. "Unemployment is falling," he said at a morning rally in Tampa, Fla. Our assembly lines are humming again. "We've got a long way to go, but, Florida, we've come too far to turn back now," he continued. We can't afford to go back to the same policies that got us into the mess. We've got to stick with the policies that are getting us out of the mess. Mr. Romney's new message of change highlights how significantly his pitch to voters has evolved since he entered the race in 2011. Back then, he devoted most of his time to attacking the president's economic stewardship, even mocking the idea of big change: a standard line back then criticized Mr. Obama as trying to "transform America" away from an opportunity society. On Thursday, it was Mr. Romney who called for transformation, of the small-government variety, saying that Mr. Obama stood for "the status quo path." The president has the same old answers as in the past: he wants another stimulus, he wants more government workers, and he wants to raise taxes. Mr. Romney appeared to be testing new language as he prepared for a major speech on the economy, which he is to deliver in Iowa on Friday, seeking to build on the energy he generated from a series of animated debate performances. In a rare moment of political self-analysis, Mr. Romney said that "the president's campaign is slipping" and attributed it to the debates. "They have helped propel my campaign, and they have slowed the president's," he said. Michael Barbaro reported from Worthington, and Peter Baker from Chicago.