name calling/branding is the resort fanatics take when they cannot rationally discuss an issue or the facts do not fit their argument. The Pro GW crowd went off the fanatic end long ago and lost any creditability, but they do have two things that many who stand up to them do not, money and political power
I'm not sure that either side is exactly lacking in money or political power. One of the characteristics that many of the tea party members share is a skepticism with regards to climate change (or global warming), and the tea party has a lot of money and political power.
That doesn't affect who is right, of course. But everyone on both sides of this debate seems to have this notion that their side is the scrappy underdog going against a political and corporate behemoth manipulating the truth for profit.