Defending yourself from tyrannical governments is precisely what 2A is for.
2A only protects you from amateurs. When the SWAT team enters your home at 3am, your precious 2A ain't gonna do squat.
2A doesn't really kick in at the sporadic SWAT team skirmishes stage .... widespread resistance and guerilla warfare against a tyrannical government is the closest modern equivalent to what 2A was designed for