U.S. President Barack Obama used his Saturday radio address to demand that Congress pass the so-called "Buffett Rule" requiring millionaires to pay at least the same percentage of income taxes as middle class Americans. "We have to make choices. When it comes to paying down the deficit and investing in our future, should we ask middle-class Americans to pay even more at a time when their budgets are already stretched to the breaking point? Or should we ask some of the wealthiest Americans to pay their fair share?" Obama said in his weekly address. The president's proposal would require those making more than $1 million a year to pay at least the same tax rate as middle class families. The rule is named after billionaire investor Warren Buffett.