A fired-up Barack Obama has lampooned his Republican rivals, saying they had taken the country backwards and were better-suited to the black-and-white TV era, as he began touring battleground states in the run-up to the Democratic National Convention.
Meanwhile, Republican presidential hopeful Mitt Romney looked to capitalise on a newly energised party fresh from its three-day convention in Tampa, Florida, where a parade of speakers blasted Mr Obama's handling of the economy, struggling in the weakest recession recovery of the post-war era.
Both candidates are criss-crossing the US, each day adding to the sense of urgency in a presidential contest that has remained tight since Mr Romney clinched the nomination in April.
The economy has been the top-rated issue in opinion polls all year, and the President is eager to turn the focus on to Mr Romney.
"Despite all the challenges that we face in this new century, what they (the Republicans) offered over those three days was, more often than not, an agenda that was better suited for the last century," Mr Obama said in Urbandale, Iowa. "It was a re-run. We'd seen it before. You might as well have watched it on a black-and-white TV."
Republicans "will take us backwards", Mr Obama said, to the age of "trickle-down, you're on your own" economics that begin with tax cuts for the rich but tax increases for the middle class.
Mr Romney campaigned in Ohio during the day - the opening of the college football season - and proclaimed it was time the country had a winning season after years of a sluggish economy and high unemployment. Referring to the number of jobless in the country, he told his own cheering crowd at Cincinnati's Union Terminal: "If you have a coach that's zero and 23 million, you say it's time to get a new coach."
He also pledged to cut the national deficit and "get us on track for a balanced budget".
But Mr Romney has yet to produce a budget for public inspection. Nor did he mention that, as chairman of the House of Representatives Budget Committee, his running mate Paul Ryan wrote a plan projecting the deficit would decline each year from 2013 through 2017, but then begin an inexorable rise again. Additionally, the national debt is projected to rise each year, from a current level of nearly 16 trillion dollars (£10 trillion) to an estimated 25 trillion (£15.8 trillion) at the end of 2022.
The Democratic convention opens on Tuesday at the Time Warner Cable arena in charlotte, North Carolina, with evening speeches by first lady Michelle Obama and San Antonio mayor Julian Castro, named the keynote speaker in a nod to Hispanic voters.