If that's the case and they need to, they'll just make it legal.
https://en.wikipedia.org/wiki/Internet_censorship_in_the_Uni...
https://en.wikipedia.org/wiki/Internet_censorship_in_the_Uni...
The US government cannot compel ISPs to block websites. The only time it was tried was in 2022 to block some Israeli piracy site, and the federal court dropped the block within weeks after being hammered with first amendment lawsuits.
What we are seeing happening in Spain, France, and all across the EU, is literally impossible in the US.