President Barack Obama's worst week of his re-election campaign began with six little words.

His assertion on June 8 that "the private sector is doing fine" was gleefully exploited by his Republican rival, former Governor Mitt Romney, and has dominated Republican TV ads ever since.

American voters have got used to Romney's political gaffes being mocked relentlessly by the Democrats. Yesterday, after days of negative headlines, Obama tried to deal with his own gaffe head-on.

Standing in front of boisterous supporters in Ohio who greeted him like a rock star, the President acknowledged that he had made his own "unique contribution" to the "gaffes and controversies" that would mark the electoral campaign over the next five months.


"It wasn't the first time. It won't be the last," he said.

The presidential election in November will be won or lost on economic recovery in America, and both candidates know it. So yesterday, Obama and Romney gave opposing speeches with their prescriptions for the economy only minutes apart in different cities of the swing state of Ohio.

The President repeated his familiar theme that the defining issue of the election is "how to create good middle-class jobs" while paying down the debt.

He compared Romney's policies to those of the previous Bush Administration blamed for the dire economic situation he inherited. His solution? To raise taxes on the wealthy, which is anathema to the multi-millionaire Romney who advocates less government spending and highlights his 25 years of experience in the business sector.

Although opinion polls failed to take off in Romney's favour after Obama's gaffe, the presidential race remains extremely tight and could go against Obama if the meltdown in the eurozone countries spreads across the Atlantic.

The past few days have seen a raft of weak economic data.

Obama's sky-high ratings of four years ago around the rest of the world, inspired by his message of hope and change, have eroded, according to a Pew Research Centre survey in 21 countries. And, in the past week he became the butt of jokes by TV comedians comparing him to the last one-term Democratic president, Jimmy Carter.

Also hanging over the campaign is a much-anticipated ruling of the Supreme Court, expected before the end of the month, which may throw out all or part of Obama's healthcare reforms on constitutional grounds. The reforms, which will provide an additional 32 million African Americans with healthcare coverage, were enacted early in 2010 after a long and bitter debate.

Money talks in this campaign like never before. Again, the Supreme Court justices played a critical role in 2010 by allowing huge amounts of money to be spent by so-called Super-PACS, by striking down a law restricting corporate and union funding of political campaigns.

Romney raised more than US$17 million ($21.7 million) more than Obama last month, although the President stands to profit more from wealthy donors from Hollywood and the gay community following his recent embrace of same-sex marriage.

So one of the key questions to be answered in the course of the campaign is the extent to which the flooding of swing states with TV ads will influence the average voter.

The US$2.7 million spent by the pro-Romney Super-PAC Restore our Future on TV spots in Iowa certainly contributed to the defeat of former House speaker Newt Gingrich in the state caucuses last January.

The other major uncertainty is whether the candidates' party base will turn out massively to vote in order to clinch the election. It seems that despite their reservations about Romney's Mormon faith, the Republican grass roots hate Obama more than the former Governor.

As for Obama, it remains to be seen whether his core constituency of black and Latino voters will bother to cast a ballot given their disappointment, respectively, on economic prospects and immigration reform.