TOLEDO, Ohio (AFP) - US President Barack Obama was in the blue-collar heartland of Ohio Monday, seeking to energize his labor union base after accusing Republican foe Mitt Romney of failing to offer “a single new idea” to solve the country’s problems.

The motorcade of the president, who arrived in Toledo Sunday, was greeted by pockets of friendly well-wishers, who carried signs saying “New citizen for Obama,” “Toledo built Jeep. Thank you, President Obama,” “Obama 2012” and “4 more years.”

Toledo is home to General Motors and Chrysler factories whose workers benefited from the 2009 multi-billion-dollar auto industry bailout championed by the president.

Obama is on a four-day “Road to Charlotte” tour taking in territory that will decide November’s election, in which his prospects are clouded by a painfully slow economic recovery and 8.3-percent unemployment.

He has already visited Iowa and Colorado and plans to make a trip to hurricane-stricken Louisiana later in the day.

Should Obama win Ohio, a perennial bellwether state and one where most polls show him with a narrow lead, he will be the hot favorite to win a second term.

No Republican has won the White House without having Ohio in his column.

Obama will travel to another swing state, Virginia, on Tuesday, before flying into Charlotte, North Carolina, on Wednesday on the eve of his big Democratic National Convention address.

Addressing supporters in Colorado Sunday, Obama rebuked Romney for failing to offer any new ideas for the country’s future. “It was something to behold,” Obama told a 13,000-strong crowd in Colorado, as he picked apart Romney’s keynote address in Florida on Thursday night, the climax of a three-day Republican convention.

“Despite all the challenges we face in this new century, what they offered over those three days was an agenda that was better suited for the last century,” Obama said.

“It was a rerun... we have seen it before - you might as well have watched it on a black and white TV with some rabbit ears.”

Democrats say that Romney, who used his convention to try to tell his personal story and improve his likability ratings, may have given Obama an opening by offering only sketchy policy stands.

They are also framing Obama as a candidate of the future, with his slogan “Forward,” and to position the older Romney - he is aged 65 while Obama is 51 - as a contender from a bygone era.

Obama said that Romney, with whom he is neck and neck in the polls ahead of the November election, had refused to reveal the “secret sauce” that would help him create jobs: “he did not offer a single new idea.”

“It was retreads of the same old policies we have been hearing for decades, the same politics that have been sticking it to the middle class for years,” the president added. He also ripped Romney for having “nothing to say” in his speech in Florida about the Afghan war, which the president has promised to end “responsibly” in the same way that he brought troops home from Iraq.

“We are bringing our troops home from Afghanistan. And I set a timetable - we will have them out of there by 2014. Governor Romney doesn’t have a timetable. I think he is wrong.”