Patrick J. Leahy

Vermont

Leahy, 66, has been steeped in some of the Senate's most polarizing debates of recent years, including nominations to the federal courts and anti-terrorism legislation.

Elected six times from a state that had never before sent a Democrat to the Senate, Leahy has crusaded for the elimination of land mines and is one of the Senate's experts on information technology issues. After the Sept. 11, 2001, attacks, he was the lead Democrat in negotiating the USA Patriot Act, insisting on balancing its surveillance provisions with some civil liberties protections. He has since criticized the administration for some of its interpretations of that law and its definition of torture.

Last year, Leahy supported the nomination of John G. Roberts Jr. to the Supreme Court as chief justice but opposed the nomination of Justice Samuel A. Alito Jr. Leahy also has led filibusters against several of President Bush's nominees for appellate judgeships on the grounds they were too conservative -- and earlier complained that the GOP held up some of President Bill Clinton's nominees.