Extremely far apart but which side is extreme?

Extremely far apart but which side is extreme?

http://www.newrepublic.com/article/119248/gop-extremism-action-rubio-immigration-inhofe-climate

Stop and think about the following  quote for a second.

""Stop and think about that quote for a second. Global warming is a worldwide problem, which means it requires worldwide action, which means the U.S. will have to be part of some kind of worldwide regulatory scheme. Inhofe won't even think about it. And while Inhofe has a reputation as an extremist, he's not an outlier here. Yes, John McCain endorsed a cap-and-trade plan when he was the Republican nominee for president in 2008. But he's basically disavowed that idea. Good luck finding a prominent Republican in office who will even speculate about such a proposal today.""

If the author cannot convince the legislators of the truth of their assumptions (and the truth of global warming is an assumption), shouldn't they question their assumptions? Here the assertion is made with no supporting evidence.

From my viewpoint, the democrats are extreme and moving to be more extreme. Why is my view wrong and the progressive view correct?

You can't change my mind by filibustering the issues and shouting down opponents. You need to engage intellectually.