Michelle Obama to Ohio supporters: Vote; a second term isn't certain CINCINNATI, OH - A marching band took to the streets of downtown here Tuesday, leading the crowd to a destination not usually associated with much fanfare: the voting booth. On the opening day of early voting in the Buckeye State, first lady Michelle Obama rallied 6,800 supporters at the Duke Energy Convention Center in downtown Cincinnati. "Here in Ohio, it is already election day," she said, flanked by a large banner that read "Cincinnati fired up! Ready to vote! The first lady encouraged the large and boisterous crowd to make the short walk directly from the rally to the Hamilton County Board of Elections where they could become some of the first Americans to cast their ballots for President Barack Obama's re-election. The latest NBC News/Wall Street Journal poll shows the president maintaining a slight lead nationally over Republican challenger Mitt Romney, and a recent polls show that lead is even bigger in Ohio. Even with the positive polls, Michelle Obama warned supporters that a second term for her husband is far from certain, which is why they need to start voting. Thirty-five days is a long, long time in an election. No one should be comfortable," she said. She later added: "I'm going to be honest with you, this journey is going to be hard, let's count on that. And there are going to be plenty of ups and downs for the rest of the way. Michelle Obama warned the crowd of apathy, recalling how narrowly her husband won the battleground state of Ohio four years ago. "Back in 2008, back then we won Ohio by about 262,000 votes," she said. Now that might sound like a lot, but when you break that number down, and you spread it across all the precincts, that is just 24 votes per precinct ... That could mean just a couple of votes in your neighborhood or your block. Obama won here in Hamilton County in 2008, a traditionally Republican county that turned blue that year for the first time since Lyndon Johnson in 1964. If Obama is able to repeat his success in the state's southwest corner, the path for a Republican to win the state becomes incredibly difficult. In 2008, an estimated 30 percent of voters cast ballots early. The Democratic National Committee and the president's campaign have tried to capitalize on getting as many votes as possible before November. The "Gotta Vote" bus tour kicked off in Iowa to encourage early voting in the Hawkeye State and will continue the tour through Ohio on Wednesday - meaning some Americans will decide with more than a month left in the campaign and before the first presidential debate. The Romney campaign countered with its own get-out-the-vote effort on Tuesday, kicking off the "Commit to Mitt Early Vote Express" tour around Ohio. In light of polls showing Romney losing this critical swing state, the campaign released a memo from Ohio State Director Scott Jennings arguing the race here remains a dead heat. "Bottom line - the race in Ohio is close, undecided voters are extremely unhappy with Barack Obama, and Mitt Romney's campaign has built a ground game that is at the very least matching Obama's while surpassing all previous Republican efforts when it comes to knocking on doors and contacting voters face-to-face," Jennings wrote.