Did you hear the one about the woman, the black guy, and the Walmart greeter?

Gloria Steinem is 73, Robert Redford and John McCain 71. McCain's mother Roberta, who just renewed her driver's license, is 96. Do they seem "out to pasture," doddering, or foolish to you?

In humor, you have to tread carefully. Unless you are going after "old folks," that is. Much has been said in this year's presidential campaign about sexism and racism. But there's another "ism" that seems to be taken for granted: ageism.

David Letterman calls presidential candidate John McCain a "Walmart greeter" and a "mall walker," according to Julie Bosman in the New York Times. She asks "Has ageism run rampant in mainstream discourse because America exalts youth?. . .is the oldster an archetype so ingrained in the American comic sensibility--a la 'Grumpy Old Men' and 'Golden Girls'--that it trumps identity in politics?"

Great question--although in fairness, ageist humor may be milder now than it used to be. When Bob Dole was running for office, Letterman said “Bob Dole is so old his Social Security number is 2. He’s so old that when he was a teenager, his cologne was New Spice. He’s so old, his Secret Service code name is The Clapper.”

Even McCain gets on board with 'the joke': "Usually, people watch my performance to see if I need a drool cup, or stumble around, or anything like that."

In Politico, Roger Simon points out that John F. Kennedy, for all his appearance of youthful vigor, was frail and ill much of his time in the office he entered at age 43. Youth alone is no guarantee of physical health, mental acuity, or fitness for office.

I'll admit that I'm not ready to give up jokes about old people myself. But I'm making a vow to find jokes where the older person comes out on top of the humor. Because what we say and how we say it makes a difference in how we see--and create--aging.

What do you think about old-age stereotypes? Age-related humor?