Grist: Any Republican who dismays conservatives these days quickly gets disciplined with the threat of being primaried - challenged from the right. This is one of the major impediments to (among many other things) legislative action on climate change.
Recall the speed with which Mitt Romney was whipped into line by Rush Limbaugh during the 2012 presidential primaries when Romney dared admit that anthropogenic climate change is real. Or ask conservative but sane ex-senators such as Dick Lugar and Bob...