Jewish groups have accused the longest-serving US senator Robert Byrd (Democrats) of making an outrageous and reprehensible comparison between Adolf Hitler's Nazis and a plan by the Senate's majority party to change a venerable practice to quash opposition. One senator urged Byrd to retract his remarks. Byrd's spokesman denied that the senator had compared Republicans to Hitler. He said the reference to Nazis in a speech on Tuesday was meant to underscore that the past should not be ignored: "All one needs to do is to look at history to see how dangerous it is to curb the rights of the minority." Byrd, a member of the minority Democrats, was speaking in opposition to threats by the Republican majority leader to force through a rule banning use of the filibuster, a parliamentary tactic by which the minority can hold up legislation, against President George W. Bush's nominations for federal judgeships. Ken Mehlman, chairman of the Republican National Committee, called the remarks "poisonous rhetoric" that were "reprehensible and beyond the pale." Abraham Foxman, director of the Anti-Defamation League, said that Byrd's remarks showed "a profound lack of understanding as to who Hitler was," and the senator should apologize to the American people.