I think America doesn't manufacture semiconductors because it is a very unclean process, full of nasty chemicals. It's expensive to make semiconductors and deal with the clean-up. There are less environmental restrictions and cheaper labor in other parts of the world.
There are a bunch of Superfund sites around Mountain View, CA that serve as a reminder about the US Semiconductor industry - Fairchild Semiconductor, Intel, National Semiconductor, Monolithic Memories, and Raytheon to name a few.
Nobody in the U.S. really wants that in their back yard. Of course we've seen the same kind of thing from fracking, and everything else that rightly should be regulated or banned.
What happens now with a defunded and purposefully dysfunctional EPA is anyone's guess. Maybe manufacturers will exploit the political climate to further destroy the environment to make a few more million or billion dollars.