Bill Clinton, the last two-term Democratic president, has the tricky task Wednesday of convincing a struggling America that a vote for Barack Obama is a ticket back to prosperity. Twenty years after the man from Hope, Arkansas won over the country at his own presidential nomination, the party superstar, who presided over a gilded era of growth, will make the economic case for re-electing Obama on November 6. Obama arrived in Charlotte, North Carolina on Wednesday afternoon as he prepared for his own convention pitch fewer than nine weeks out from an election that is too close to call and hinges on a handful of battleground states. In a blow to Democrats, the threat of severe weather forced the president\'s renomination address on Thursday to be moved indoors from a massive American football stadium, the kind of arena that served him so well in 2008. A campaign advert swamping TV networks previewed the message voters can expect from Clinton on Wednesday night when the silky political veteran returns to the spotlight with a prime-time address to a packed convention hall. \"This election to me is about which candidate is more likely to return us to full employment. This is a clear choice,\" he says in the ad. \"The Republican plan is cut more taxes on upper income people and go back to deregulation. That\'s what got us into trouble in the first place. \"President Obama has a plan to rebuild America from the bottom up, investing in innovation, education and job training. It only works if there is a strong middle class. That\'s what happened when I was president. We need to keep going with his plan.\" First Lady Michelle Obama made an impassioned plea on the opening night of the convention, holding up the president\'s childhood as the son of a struggling single mother as evidence he understands the plight of ordinary Americans. \"She was absolutely magnificent. Awesome!\" Texas delegate Yvonne Massey Davis, one of the thousands of party faithful gathered in Charlotte, told AFP. \"She spoke not only as a professional woman but as a mother and a wife.\" Throughout Tuesday\'s opening night, speaker after speaker portrayed Romney, who was born into wealth and amassed a $250 million fortune running private equity firm Bain Capital, as a ruthless corporate raider who just didn\'t get it. \"The middle class has gone and everyone is struggling to put their children through school. I think Romney doesn\'t understand, he came up from a very privileged background,\" said 58-year-old Massey Davis. The arena in Charlotte, crammed to 15,000-seat capacity with Democratic delegates and Obama supporters, erupted whenever Romney came under attack, with chants of \"Four more years! \"Four more years!\" echoing around the auditorium. Democrats have made hay out of the wealth issue throughout the presidential campaign, attacking Romney for keeping much of his fortune in offshore havens and pressing him to release more tax returns. Republicans have in turn accused Obama of disparaging success and waging \"class warfare,\" while failing to spur a more robust economic recovery or bring the unemployment rate down from a stubborn 8.3 percent. Clinton\'s economic pitch could be a hard sell to many Americans still feeling the affects of the \"Great Recession,\" but Democrats said he was just the man to appeal to white, working-class men in swing states. \"He\'s able to reach out with his charisma to people who will not listen to President Barack Obama if for no other reason than his color,\" Jonice Crawford Butler, a Democratic volunteer in her 60s from Michigan, told AFP. National polls put the rivals neck-and-neck, but a closer inspection of swing states reveals that Romney has his work cut out, especially as the bounce he was hoping for from last week\'s Republican convention has failed to materialize. Republican attack dog John Sununu, a former New Hampshire governor, said Clinton\'s \"blast from the past\" appearance may well \"induce nostalgia for the days of balanced budgets and bipartisan accomplishments.\" \"In ushering in new levels of fiscal recklessness, President Obama doesn\'t simply depart from the Clinton legacy -- he shatters it with a sledgehammer and runs over it with a steamroller,\" he said, in the Manchester Union Leader.