Newt Gingrich called the comments "beyond the pale" and demanding that Barack Obama apologise on De Niro's behalf.
"What De Niro said last night was inexcusable and the president should apologize for him. It was at an Obama fundraiser, it is exactly wrong, it divides the country. What de Niro said was beyond the pale and he should be ashamed of himself," he said at an event in Louisiana.
Adapting a common Gingrich riff against America's "elites" and railing against the high price of petrol, the Republican hopeful said the Raging Bull star had "missed the whole point".
"De Niro is rich enough he probably hasn't noticed the price of gasoline. He's successful enough he probably doesn't notice the unemployment rate and as a Hollywood actor he may well be short-sighted enough he hasn't seen what the deficit is going to do to our children and our children's children," he said.
Michelle Obama's office said the joke was "inappropriate."