I'm confused by the US conservatives' full court press for fossil fuels and against wind/solar.

It's almost all tribalism: the left is for it, so they're against it. They have a partially valid point that a lot of so-called environmentalists are anti-progress degrowthers, but the response should be to demonstrate that clean energy (including nuclear) is very good for growth. When conservatives do what they're supposed to and let market forces work, you see things like Texas producing more renewable energy than California.