US President Barack Obama has used the first official rally of his re-election bid to brand Republican rival Mitt Romney as a willing rubber-stamp for failed policies championed by extreme House Republicans.
Mr Obama told an enthusiastic crowd in Columbus, Ohio, that America had a tough time rebounding from a deep recession. But he said it has come too far to turn back now.
The noisy rally at a campus basketball arena was the first of two on Saturday for the Democratic incumbent.
Later, he will speak at Virginia Commonwealth University in Richmond, Virginia. Both Ohio and Virginia are seen as critical states to the election outcome.
Mr Obama has raised cash and given campaign-like speeches for months, but the latest rallies are the first events formally organised by his campaign.
Official campaign rallies can free Mr Obama up to take more direct aim at Mr Romney. Until now, he has used Mr Romney's name sparingly, often choosing instead to cloak his criticisms in attacks against generic Republicans.
New job numbers on Friday highlighted the challenge Mr Obama faces. Job growth slumped for a second straight month. The unemployment rate dropped to 8.1% in April, but largely because more people stopped looking for work and therefore were no longer deemed unemployed.
In the face of continued economic unease, Mr Obama's campus rallies were intended to recapture some of the youthful, hopeful energy of his 2008 campaign - and target a voting bloc, young people, that was crucial to his victory four years ago.
"For the last few years, the Republicans who run this Congress have insisted that we go right back to the policies that created this mess," Mr Obama said, even though Democrats control the Senate. "But to borrow a line from our friend Bill Clinton, now, their agenda is on steroids," he said.
Mr Obama said Mr Romney seems to believe if wealthy Americans like him or big corporations get richer, the country will prosper. But he said bigger profits have not led to better jobs, and Mr Romney "doesn't seem to get that".