In a speech on the night of the final Democratic primaries that recognized Sen. Barack Obama's emergence as the presumptive Democratic candidate for president, Sen. John McCain stood in front of a newly unveiled campaign poster inscribed with the slogan "A Leader We Can Believe In."
Unlike his official campaign colors, which are predominantly a rich blue, the sign behind McCain was green. That may have been an unfortunate choice.
Unwittingly no doubt, the green background provided a crude "green screen," the background used in television to project video behind the reporter. It is probably best known as a way for television weathercasters to look as though they're standing in front of a meteorological map or animated graphics.
In McCain's case, the green background allowed Comedy Central's Stephen Colbert to issue one of his famous "Green Screen Challenges."
"By speaking in front of a green screen, John McCain issues a bold challenge to Americans to make him seem interesting," the political satirist said.
Dozens of people responded, posting video on YouTube ridiculing or mocking McCain. In one of them, McCain is shown in file tape standing beside President Bush -- including his bear hug embrace of the president in 2004 -- while, in an excerpt from the speech, he says, "You'll hear from my opponent's campaign in every speech, in every interview, in every news release that I'm running for President Bush's third term. Why does Sen. Obama believe it's so important to repeat that idea over and over again? Because he knows it's very difficult to get Americans to believe something they know is false."
In another video, McCain's image is placed Zelig-like into archival video of President Kennedy, an address by a young Queen Elizabeth and Martin Luther King's "I Have A Dream" speech. At the end, the words "John McCain. He's That Old" appear on the screen.
In yet another YouTube video, McCain is seen praising Sen. Hillary Clinton while behind him runs a clip from the town hall meeting last fall at which a supporter says, "How do we beat the bitch?"
Less skewering, one video shows McCain speaking solemnly while people in outlandish outfits dance and gyrate in the background; another shows Superman flying in the air.
The lesson for candidates for elective office: Be careful about standing in front of anything green.