What TV news I watch is from an elliptical trainer, and I work hard to avoid commercials — every time you listen to a commercial the hucksters win — so I skip channels a bit and set the TV to mute fairly often and listen to an audio book. So I'm often confused about who said what on which program, but I got the clear message that my fellow Libs Stephen Colbert, Jon Stewart, Chris Hayes, and/or Rachel Maddow got fairly shocked by the idea of a Republican candidate for office addressing gun enthusiasts and bringing up potential use of firearms to defend oneself against — i.e., shoot at with intent to wound, kill, or maim — various folk in the Federal government.
Uh, yeah. That goes with a reading of the Second Amendment that I heard from the 1960s on. The logic is straighforward. The Second Amendment is second only to the First — free speech and all that — in that the Right to Bear Arms ensures the other rights against the threat of a tyrannical government.
After all, Tom Jefferson and the guys held as self-evident axiomatic "that all men are created equal, that they are endowed by their Creator with certain unalienable Rights [...] That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, --That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness."
Under the Bill of Rights that we eventually got from the Revolution (or Counter-revolution, if that's your theory), citizens of the Republic could exercise our rights and peaceably assemble and shoot our mouths off "to petition the government for a redress of grievances." But let's say there's no redress: not this time, not for a long time. Let's say the newfangled Federal government, or "any Form of Government" starts destroying rights rather than protect them? Well then it is our right, nay, our duty to try "to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as [...] shall seem" to us "most likely to effect [... our] Safety and Happiness" and renewal of The Tree of Liberty.
Governments, however, don't like to be altered or abolished, and they fight back, with guns. (Mr. Jefferson was clear as to just what would water/manure the figurative Tree of Liberty.)
Now as a practical matter, the real revolutionary parts of revolutions are often pretty bloodless in the initial takeover. The fighting back comes after a bit, and what decides it isn't usually the weapons the peasants and revolutionary pros have but, instead, which way the troops finally decide to point their weapons. When the soldiers refuse to fire on the crowd and shoot instead their officers — or when military leaders join the rebels — that's when the revolution wins, at least for a while (until it gets betrayed ... and eventually the cycle starts all over again).
Still, at least in the initial stage of the revolution and maybe in the following guerilla warfare, it helps to have a well-armed populace to secure The Right of Revolution.
Which "Right," unfortunately, usually means some hotheads or fanatics gunning down cops or a standoff like Ruby Ridge and the siege at Waco leading to a skirmish and death. Or Shay's Rebellion. Or leading up to something as major as the US Civil War.
Which leads to the side of the Second Amendment coming from the other side of Tom Jefferson's life and that of a goodly number of the Founders and Framers: The need for well-armed White folk to put down any "servile insurrection" (or Indian attacks), or, later, just "uppity n*ggers." "[T]he right of the people to keep and bear arms," except for brief periods, meant the right of White folks to keep firearms, while you can — or more likely I can — get arrested for "open carry" of a knife.
(The joke is that a Liberal is the guy who brings a knife to a gun fight; in terms of "home defense," I live the joke.)
Anyway, Jon or Stephen or Chris and/or Rachel shouldn't be surprised at gun fans indicating a willingness to shoot agents of the Federal government: Federal Marshals, FBI, ATF — whatever. That's part of the theory. It's also close to rebellion, insurrection, or treason, and the Federal government can be expected to shoot back. Maybe not Sherman's march to the sea this time, or even a drone strike, but far heavier shit than dreamt of by people who hold such theories.
And if they keep talking that way and arming themselves quite so assiduously, then we can expect even more militarization of our police forces and the irony of the Second Amendment working not to preserve the Republic but to put it in danger.