In a Jan. 7 town hall event, President Obama bristled at the suggestion that he has a plan to confiscate Americans' guns. (CNN)

As we've noted already this week, President Obama has a habit of keeping his emotions in check, except when it comes to the issue of gun control.

At Thursday's CNN town hall event on that very topic, Obama didn't shed tears, but he did get testy with CNN host Anderson Cooper over the suggestion that he wants to confiscate guns from American citizens.

The implication that Obama and other gun-control advocates want to curtail Second Amendment rights — or even take guns away from law-abiding citizens — is at the heart of conservative arguments against the president. Donald Trump has repeatedly accused Obama of “trying” to take citizens’ guns away, while a Ted Cruz campaign website featured a headline reading “Obama wants your guns” just this week.

So when Cooper asked Obama, "Is it fair to call it a conspiracy?" it got personal.

"What are you saying?" Obama asked, visibly taken aback. "Are you suggesting the notion that we are creating a plot to take everybody's guns away so that we can impose martial law is a conspiracy? Yes, that is a conspiracy."

Obama, of course, has never actually proposed confiscating guns. He has proposed an assault weapons ban and favors outlawing high-capacity magazines. But the fear that the president wants to (eventually) take away Americans' already-owned guns persists.

To gun rights advocates, it persists in part because of Obama's repeated mentions of Australia, a country that banned semiautomatic rifles and shotguns and bought back nearly 1 million firearms from citizens in the wake of the Port Arthur shootings in 1996. While Obama seeks to use Australia as an example of a country that took what he calls "common sense" steps on gun control, his opponents see it as a subtle move toward enacting the same laws in the United States and taking back guns.

Obama countered that the "conspiracy" is really perpetuated by conservatives for political reasons — or by the gun lobby for "commercial reasons." (Gun sales typically spike after mass shootings. Obama even said Thursday that his presidency has been a boon to gun manufacturers. And it has.)

While Obama touts "common-sense reform," gun rights activists remain passionate about their firearm ownership. And ultimately, that passion makes the Second Amendment a powerful political motivator. Don't expect the "Obama wants your guns" theory — and the motivation it entails — to go away anytime soon. No matter how much Obama thinks it's a conspiracy.