Disagree.
This would degenerate into low level street clashes where militants try using protestors as human shields. Marshall Law will be declared, and we have the tools to pick people out of crowds who are carrying guns. Suspension of Constitutional rights would come before anyone is allowed to organize terrorist attacks at that level.
If anti-government groups try to form en masse, they have some serious logistical challenges. If they form up in cities, cities rely on infrastructure. It's not hard to close the roads, shut down utilities, demolish food distribution centers. If they form up rurally, they can't really do much in the country besides attack infrastructure leading to the cities. It's not hard for the government to bring out heavy weapons to clean them out, small arms are no match for mortars, helicopters and APCs.
This has been an information war to this point, which is why it seems so static. Once it becomes kinetic, people's outlook changes dramatically. They just want to get back to normal and whoever is seen as legitimate will get support from the people. After that, the winner gets to declare the prevailing ideology, institutions that don't support it are cancelled, and people fall in line.
While I understand the risk of predicting a short engagement, it's very difficult to see how this would go on for long given the current amount of information that exists on every American. It's theoretically possible to do a search for every Communist and get a fairly accurate list. That's a tool that's never been brought to bear in an insurgency before, I'm curious about how it would work.