Moynihan called Bradley "a man with heart and courage and stamina."
"You can't govern, as Woodrow Wilson said, without those qualities. He has shown them all his life in one way or another," he said.
This pat on the back from Pat Moynihan is just the latest piece of good news for Bill Bradley, reports WCBS-AM reporter Paul Murnane.
While national polls have indicated that Gore is still the Democratic leader, recent polls in New Hampshire and New York have shown a tight race between Bradley and the vice president.
An appreciative Bradley acknowledged that his campaign is "up against an establishment," but he said that Moynihan's endorsement was "important. I think people will take notice." Bradley also called Moynihan "a distinguished giant."
Asked why he preferred Bradley over Gore, Moynihan responded simply, "Nothing is the matter with Mr. Gore, except he can't be elected president."
Moynihan, a New York Democrat who is retiring from the Senate, and Bradley have been friends for more than two decades. Bradley served three terms as a New Jersey senator, and spent time with Moynihan on the Senate Finance Committee.
The announcement was made at the 92nd Street Y, where Bradley often worked out while winning two NBA title with the New York Knicks. It was an unusual location for a political announcement; the "Y" is better known as a spot for cultural events and book readings.
Moynihan held up a copy of Bradley's 1996 memoir, Time Present, Time Past," and called it "a brilliant book." He again quoted Wilson as saying that presidents come from "wise and prudent athletes, a small class."
Bradley, a Rhodes Scholar, was an All-American basketball player at Princeton before joining the Knicks.
Moynihan is the third senator to endorse Bradley, joining colleagues Paul Wellstone of Minnesota and Bob Kerrey of Nebraska.
Gore has been endorsed by more than 100 members of Congress.