OOOooooohhh I'd LOVE to see them try. They would set up the scenario that Patriots have worried about for decades now. So here's a bit of strategic thinking: DC could be entirely shut down, no one in and no one out, with enough military personnel guarding bridges, roads, and metro lines into the city. Shut down any helipads by parking large vehicles on them, and take over Dulles Airport.... and you have a city frozen in place. No food going in, and shut down all utilities. Impose a round-the-clock curfew and arrest anyone on the streets.

Then start going door to door looking for specific DS targets.

DC would capitulate in about 3 days and the residents would be EAGER to turn over any traitors they could find, just to get their lives back.

I don't know this for a fact, but I highly suspect that military plans have been in place for years for just this eventuality.