[cnn-photo-caption image= http://i.l.cnn.net/cnn/2008/images/01/17/art.leahy.gi.jpg caption=" Sen. Patrick Leahy is backing Obama."] LAS VEGAS, Nevada (CNN) - Vermont Sen. Patrick Leahy, the powerful chairman of the Judiciary Committee, will back Sen. Barack Obama’s bid for president, three Democratic sources familiar with the pending endorsement tell CNN - the Illinois senator's fourth Senate endorsement in a week.
Leahy, first elected in 1974, is charged with vetting nominees to the federal bench, including the U.S. Supreme Court.
“Pat Leahy is one of the finest members of the U.S. Senate, and he sees the kind of possibilities that Barack Obama can bring to effect change to this country and world,” said one of the sources.
UPDATE: On a conference call with reporters, Leahy said he endorsed Obama because he believes he can bring reform to the nation's health care system and schools, and end the Iraq war. "Barack Obama gives us that hope," he said, saying the Illinois senator "represents the America we once were, and want to be again."
"We need a president who can reintroduce America to the world, actually reintroduce America to ourselves. I believe Barack Obama is the best person to do that," said Leahy.
He also said that "My endorsement is not in opposition to either Sen. Clinton or Sen. Edwards, both of whom I know and admire. I'm looking at who can do this best, and I believe Barack Obama can."