I agree with most of what you write, except to say there's very little academic Marxism in the hard sciences. Most scientists are determinedly apolitical. And even in the case of Kennewick man, scientists were solidly behind free inquiry. If we slipped up, it was by not getting behind the archaelogical community when NAGPRA was first proposed; that single pernicious piece of legistlation has devastated pre-Columbian archaeology in this country.
What I find significant about Kennewick man is that we were betrayed by both Bush and Clinton. This was a case where Bush could have gone a long way to fight-off his anti-science reputation. He blew it. And don't get me started on McCain, who tried to sneak through an amendment to close the Kennewick 'loophole'.
It's hard not to paint with a broad brush in these short posts. Have you read -- or tried to read -- Scientific American lately? Political correctness had permeated the magazine last time I checked. Maybe that's media Marxism, not academic Marxism, but it serves as a filter to the public in presenting scientific issues. What I also had in mind when posting was the Sagan model. I consider astronomy a "hard" science; I don't know how you'd define it. Where was the broad scientific community in opposing his outrageous Nuclear Winter model?
You have my total agreement on Kennewick-NAGPRA. The legislation was indeed pernicious and it's disgusting to see pols and bureaucracies like BIA and the Corps of Engineers playing to race-and-religion-based "entitlement" voting blocs anytime but especially when scientific integrity is at risk.