Whatever else he may have been, Richard M. Nixon wasn't generally known as a comedian. So many American TV viewers were surprised 50 years ago to see the Republican presidential nominee pop up on the hit comedy show "Rowan & Martin's Laugh-In."

The date was September 16, 1968, less than a month after the turbulent riots at the Democratic National Convention in Chicago and two months before the November elections. Nixon's appearance was brief, about five seconds in all, but memorable. Like a long list of Laugh-In guests, he looked straight into the camera and delivered one of the show's trademark phrases, "Sock it to me!" Even after a reported six takes, it sounded more like "Sock it to me?"—as if Nixon himself couldn't believe he was saying it.

Nixon, who famously distrusted the media, chose his TV appearances carefully. According to the Associated Press, he hadn't been on either "Face the Nation" or "Meet the Press" in two years. His aides reportedly advised against appearing on "Laugh-In," too, given its liberal attitudes toward subjects like sex, recreational drug use and the war in Vietnam.