In a stinging letter signed by fellow committee members, U.S. Rep. John Yarmuth, D-Ky., has asked House Oversight and Government Reform Subcommittee Chairman Patrick McHenry, R-N.C., to apologize for impugning the character of White House consumer adviser Elizabeth Warren at a recent hearing.During the argument, Maryland Congressman Elijah Cummings, who also signed Yarmuth's letter, interrupts McHenry and suggest he check the schedule with his staff before suggesting Warren is lyingHere's part of the exchange between McHenry and Warren on Tuesday.Since the dust up, Warren's supporters have blasted the GOP lawmaker on his Facebook page, calling him a "rude bully" who should be ashamed for his behavior."We believe you should apologize to the members of the subcommittee, as well, for denigrating the proceedings and potentially compromising our ability to conduct our important work in the future," Yarmuth says.