Reuters President Barack Obama's grim warnings about the state of the US economy could backfire on him by undermining a key goal of his re-election campaign - restoring the confidence of Americans. In his drive to push a $447 billion jobs package through Congress to spur hiring, the Democratic president has spoken of an economic emergency that he wants Congress to fix by approving his ideas to create jobs. But the more Americans worry about the economy, the less likely they are to spend, jeopardizing any upside from Obama's jobs program.The president is also trying to move the dial of public opinion against Republicans by crisscrossing the country to push for a “fairer” American economy. He has voiced understanding for the Occupy Wall Street movement protesting policies during the recession that critics say helped banks but provided little relief for high unemployment and job insecurity. By siding with public anger against big banks and pushing for higher taxes on millionaires, Obama may make Americans more unhappy about wide income inequality, which could hurt his re-election bid. “Populism is predicated on people feeling that they are getting the short stick,” said Jim Kessler, vice president for policy at Third Way, a nonpartisan think-tank in Washington.“In tough economic times, optimists win presidential races and pessimists lose. It is very hard to be both a populist and have a sunny view of America's future,” Kessler said. US consumer sentiment slumped in early October as worries about declining incomes drove consumer expectations down to the lowest level in more than 30 years. Some past American presidents, like Republican Ronald Reagan and Democrat Franklin Roosevelt, managed to project beyond tough economic times and win re-election despite high US unemployment. Obama must perform the same trick. Reagan was re-elected in 1984 after the US jobless rate improved from 9.5 percent to 7.2 percent. No president since then has won a second term with unemployment above 7.2 percent. The White House says Obama is simply being straight with the country about the risks ahead.“You have to be honest with people that, obviously, the economy is growing at a very, very slow rate, we're not making a dent on jobs, and you have this Europe thing overhanging,” a top White House official told reporters in a recent briefing. __