John Anderson

U.S. Sen. Patrick Leahy: Getty Images PhotoU.S. Sen. Patrick Leahy (D-Middlesex) seems to be everywhere these days, from fighting to ban cluster bombs in Dublin to challenging big oil company executives on the Senate floor. He'll even make an appearance in this summer's eagerly awaited Batman flick, "The Dark Knight."

Although Leahy himself, who chairs the Senate Judiciary Committee, is no superhero, his political prowess is matched by few. Congress.org, a non-partisan website that ranks politicians' influence in Washington, named Leahy the fourth most-powerful U.S. senator in the nation and the fourth most-powerful man in the Democratic Party.

But few could have predicted Leahy's rise to power, his longevity or his success. First elected in 1974, he became the first and only Democrat to represent Vermont in the U.S. Senate; at the age of 34, he was the youngest as well.