Welcome to TFL. The sad truth is, the "unthinkable", Constitutionally, will be Federal units, probably military. (In fact, I was once on very good terms with the then head of the Marine Weapons R&D program. About 6 years ago, he told me he believed that the American public would have to be "pacified" in the near future! This was in response to a question about the future of American gun ownership.) Yes, this will be in opposition to the Posse Comitatus Act, but you spoke of the abrogation of the Constitution, so why not other laws..."SWAT" refers to police units.
Those in Federal Law Enforcement agencies that have a slanted view against firearms ownership are not really comfortable with firearms hobbyists and open dissemination and discussion of leading-edge firearms technology. "The truth shall set you free", and tyrannical folk everywhere want to limit your access to it. Viewed in that light (and the already mentioned applicability of SWAT articles to the tactically aware citizen), it should be fairly obvious whose side SWAT is on. Yours.
And mine, too. SWAT and TFL are anti-tyrant, pro-American, pro-technology, pro-time-tested tactics, pro-Peace Officer, pro-Military,and, by golly, pro-fun. (Can you tell I love this mag?)
Let go of any preconceptions you have, read both this site and the magazine honestly, and if you see any contradiction after careful perusal, speak up. I first ran across Rich online 5 or 6 years ago. It was obvious he had a lot of knowledge about firearms, tactics, and politics, but what impressed me was his willingness to admit when he was wrong, and change accordingly. I reckon if we were all that ready to evolve mentally, there'd be a lot less friction in the world.