What is That Dog Don't Hunt?
1.
An obviously
As he faced the blank stares of the members following his proposal, someone whispered offcamera, "Well. That dog don't hunt."
2.
pseudo-country-bumpkin wisdom uttered in response to news item or rumor designed to scandalize a political opponent.
The idea is that the rumor is either very easily refuted or is unimportant to the public, and thus is as worthless as a dog who won't hunt.
Bush is trying to spread rumors about Kerry's Vietnam record but that dog won't hunt.
3.
1. a way of saying a particular man is a homosexual, wimp or sissy. used by the Bush administration in the campaign against Kerry by using a picture of a fox hound wearing a tutu with the caption "that dog don't hunt," referring to the eventual state of the nation if Kerry had won.
2. a way of saying you or someone else is not interested in a particular activity.
Joe: <to Rick> I heard you were going to go rock climbing with Jim tomorrow.
Rick: uh uh, that dog don't hunt.