WASHINGTON – Al Gore said Sunday that Hillary Rodham Clinton's campaign for the White House helped change society's perception of women.

But the former vice president, who has endorsed Barack Obama, demurred when asked whether the New York senator was treated unfairly during the campaign because of her gender.

“I think that women often face these kinds of challenges, of course, in our society,” Gore said in a broadcast interview.

“But I think that she did an amazing job in changing that, as I think Senator Obama and Bill Richardson, where Hispanics are concerned, also made it possible for our country to move on into the 21st century and say, 'Wait a minute, these old things that held us down in the past, we're now within sight of a time when we can move beyond that,'” Gore said.

Obama defeated Clinton for the Democratic nomination in a matchup that featured a black man against a woman. Obama clinched the nomination in June, becoming the first black candidate to represent a major party in the race for the presidency.

Some of Clinton's supporters complained that she was the victim of sexism, particularly in the media.

Richardson, the governor of New Mexico, also ran for the nomination, though he dropped out early in the race. He has since endorsed Obama and campaigned for him.

Clinton has pledged to campaign for Obama, though their relationship remains the subject of much speculation. Some Clinton supporters, whom Obama will need to win in the fall, have called for Obama to tap Clinton as his running mate.

Obama, however, has been mum about the process of choosing a vice presidential candidate.

Gore served eight years as Bill Clinton's vice president. He said Sunday that he considers the Clinton to be good friends, though he said he has not spoken with either of them in several months.

Gore appeared on “Meet the Press” on NBC.