But Vice President Biden brought it up within the first half-hour of the vice president debate on Thursday, also mentioning Rep. Paul Ryan's (R-Wis.) remark that 30 percent of Americans want the "welfare state."
Noting that Romney opposed the auto bailout -- which both the George W. Bush and Obama administrations supported -- Biden said Americans should not be surprised by Romney's economic policies.
"It shouldn't be surprising for a guy who says 47 percent of the American people are unwilling to take responsibility of their own lives," said Biden. "My friend [Ryan] recently said in a speech in Washington said 30 percent of the American people are takers. These people are my mom and dad, the people I grew up with, my neighbors. They pay more effective tax than Gov. Romney pays in his federal income tax. They are elderly people who in fact are living off of Social Security. They are veterans who are fighting in Afghanistan right now who are not quote, not paying taxes."
Biden also invoked Grover Norquist, the conservative president of Americans for Tax Reform, criticizing Republicans for consistently signing his pledge vowing not to raise taxes.
"Instead of signing pledges by Grover Norquist not to ask the wealthiest among us to contribute to bring back the middle class, they should be signing a pledge saying to the middle class, 'We're going to level the playing field. We're going to give you a fair shot again. We are going to not repeat the mistakes we made in the past by having a different set of rules for Wall Street and Main Street.'