Later Obama said: "It's time to apply the same rules from top to bottom: No bailouts, no handouts, and no copouts."
On Tuesday night the former Massachusetts Governor released tax data showing his income in 2010 was a jaw-dropping US$21.7 million ($26.7 million), putting him firmly in the camp of the "1 per cent" targeted by the protesters of Occupy Wall St.
Obama said: "We need to change our tax code so that people like me, and an awful lot of members of Congress, pay our fair share of taxes."
The President tackled the issues that have come to dominate the Republican campaign during which he has been called a fan of big government intending to put in place a "European socialised welfare state".
"Regulations don't destroy the free market," he retorted. "American values of fair play and shared responsibility will help us protect our people and our economy."
He also dismissed accusations that he was resorting to "class warfare" after a speech touched on similar themes in Kansas last month. "Asking a billionaire to pay at least as much as his secretary in taxes? Most Americans would call that common sense."
America has been treated to the spectacle of a Republican Party tearing itself apart during the contest for the nomination which has increasingly focused on the wealth issue and the politics of envy. Obama, as the Democratic incumbent who is not facing a competitor, until now has kept out of the debate.
Obama stressed: "We don't begrudge financial success in this country. We admire it."
Speaking earlier in Tampa, Florida, Romney said he expected "more divisive rhetoric" from the President in his address. The former Governor, who had emerged as the Republican front-runner, has faced a surge from former House Speaker Newt Gingrich, whose renewed popularity - which had earlier ebbed and flowed - led to his victory in the South Carolina primary.
However, Gingrich's rise has not been to the liking of many party elders, who remember his divisive record as Speaker when he presided over the shutdown of government in a duel with President Bill Clinton. Romney, in a TV debate in Florida on Tuesday, went after Gingrich for being a paid lobbyist for failed mortgage giant Freddie Mac, which had to be rescued by taxpayers.
The Romney campaign prompted Gingrich to release partial details of his relationship with Freddie Mac showing that he was a "consultant" for the bank. Yet Romney has failed to seal the deal as front-runner. The stalemate has led some party pundits and editorialists to issue urgent appeals for new candidates.
Reflecting the fact that the election in November will be won or lost on the state of the economy, foreign policy took a back seat in Obama's speech.
Yet the carefully constructed address began with boasts that Obama had ended the war in Iraq and killed Osama bin Laden and he rounded it off with a warning that "all options" remained on the table over Iran's nuclear programme.
His point was that unity delivered results. But he recognised that in this polarised Congress, such appeals for team-playing were likely to fall on deaf ears. "I intend to fight obstruction with action," he said, as he threw down the gauntlet to legislators and urged them to draw up bills ranging from clean energy to mortgage refinancing that he would sign "right away."
In the detail what he said
Taxes: The wealthy should pay their fair share in taxes. Anyone who makes more than US$1 million should pay a minimum tax rate of at least 30 per cent.
Education: Pushed measures for college affordability. Challenged state Governments to require students to stay in school until they graduate or turn 18, as 20 states already do.
Housing: Proposed a nationwide programme to allow homeowners with privately held mortgages to refinance at lower interest rates. Congress would have to approve, a difficult hurdle.
Immigration and workforce: Reiterated a call for comprehensive immigration reform. Suggested creating a Veterans Job Corps to help communities hire veterans.
Trade enforcement: Called for the creation of a new trade enforcement unit that would go after unfair trade practices around the world, including China. Called for better inspections to stop counterfeit, pirated or unsafe goods from entering the US.
Using war savings for infrastructure: Proposed using half the savings achieved by winding down the wars in Iraq and Afghanistan to cover costs of new investments in infrastructure. Wants the money to go toward fixing existing roads and building new high-speed rail projects. The other half of war savings would go towards reducing debt.
Outsourcing/insourcing: Proposed eliminating tax incentives that make it more attractive for companies to ship jobs overseas. The proposal would require American companies to pay a minimum tax on overseas profits in order to prevent other countries from attracting US businesses with unusually low tax rates. Wants to eliminate tax deductions companies receive for shutting down factories and moving production overseas. Wants to create a new tax credit to cover moving expenses for companies that close production overseas and bring jobs back to the US. Wants to reduce tax rates for manufacturers and double the tax deduction for high-tech manufacturers.
Energy: Directed his Administration to develop a plan for safe extraction of natural gas from shale deposits. Would offer incentives to manufacturers to boost the energy efficiency of the industrial sector by upgrading equipment and eliminating wasted energy in their facilities. Will direct the Defence Department to make the largest renewable energy purchase in history - 1 gigawatt, or 1 billion watts. Solar energy zones and wind energy areas to be established on public lands.
- AP