Jim Martin, founder and head of the 60-Plus Association, says recent statements by Democrats intimating McCain's age makes him unfit to lead amount to discrimination, The Washington Times reported Monday.
"Ageism is one of the last remaining prejudices that parades openly in our society," Martin, 72, told the Times, adding that many world leaders have made their mark well into their senior years.
As examples, Martin points to Winston Churchill, who was 80 when he left office, and West Germany's Konrad Adenauer, who served as chancellor until he was 87.
"I just saw and spoke with John McCain last week and frankly, physically and mentally, he's on top of his game," Martin said to the Times. "He looks tough as nails and he is."
If he wins the vote in November, McCain, R-Ariz., would be the oldest person elected to the U.S. presidency.
Martin Bashir resigns from MSNBC over Sarah Palin comments
Texas principal bans speaking Spanish, stirs controversy