What message is the text trying to impart with the examples of Clayton Williams and George Bush with respect to media coverage?

It want to let all know that humor has no place in Politics. You should know the Clayton lost 1990 Governor elections due to one humorous comment. That comment led to his defeat against his opponent Ann Richards beat him by just a hair. A moment before the comment, it was eminent that he will win, and later George W. Bush also showed interest in him being up for presidential elections. However, Clayton and the whole political world cannot forget the humorous joke that made him lose.

Explanation:

Clayton was a big businessman, and was a contender for Governor in 1990. He could have easily won but one humorous comment, made him lose the election. And that is what relates with media coverage.