The famous philosopher Montague Python devised the most popular circular argument of all times when he posited the hypotheses that contradicting is a legitimate, scholarly method of argumentation and he subsequently spawned a cottage industry in academic circles for professors and PhD candidates to assert the converse theorem: "No; it isn't!"
The Republicans have adapted the Pythonesque attitude regarding the possibility that global warming will kill off all the polar bears (even the massive colony of expat white bears living in zoos around the world?) by disqualifying any scientific warnings designed to elicit sympathy for the gigantic brutes.
The Democrats have embraced the challenge in such a wholehearted and enthusiastic way that some observers are alarmed about the possibility that the Democrats are showing symptoms of addiction in their compulsive responses to the Republican invitations to put aside substantive topics and, instead, waste some campaign time by continually injecting new scientific information into the argument which, by the Republican ground rules, automatically disqualifies the material that is (in the Republicans' august opinion) worthy of a room of its own in the Mad Scientists Hall of Fame.
Here is a hypothetical transcript of how to play the game:
Dem: A new scientific report says that all polar bears will drown because the polar ice cap is melting.
Rep: Where does it say that in the Bible?
Dem: But if you read the report, surely, you will admit that without a polar ice cap, the polar bears will soon disappear form this earth.
Rep: Don't call me Shirley.
Dem: So you don't care if all the polar bears drown?
Rep: Polar bears are known for their remarkable long distance swimming ability, polar bear skeletons have been found on Samoa. (Republicans are not confined to reality. For Democrats, truth is a self imposed restriction limiting their retorts.)