Sure, you can get chips within some limitations - in fact I believe some chip fabs have been moving back onshore. Can you get screens? I remember coverage maybe 20 years ago about Zenith closing the last TV manufacturing in the USA, and while that was in the days of CRTs I can't imagine that a lot of new panel manufacturers are here.
Interesting point. I'm not really seeing the bottleneck with respect to defense sustainment though.
In terms of critical defense: L-3, Honeywell, Rockwell Collins, and Elbit (Israel) are a few major players off the top of my head that cater to domestic weapon system displays.
In terms of consumer displays: Japan, Korea, and Taiwan are allies. Humoring a doomsday isolation scenario with consideration towards America's disposable first-world couch potato culture, there's probably enough TVs/monitors in existing circulation throughout the country to sustain even the most improbably protracted conflict, let alone used surplus being auctioned off by the pallet for pennies on the dollar. Might even resuscitate a dead repair trade and create a few meaningful jobs too. Of course, this all assumes the government doesn't acknowledge a supply deficiency and fails to seed the capability need.
Don't get me wrong. I agree that the status quo of domestic technology production isn't exactly a self-lubricating wheel and leaves much to be desired...but it's not exactly dead in the water either.