(CNN) -- Is the anger in American politics edging towards violence?
A man is shown legally carrying a rifle at a protest against President Obama in Phoenix, Arizona.
About a dozen protesters carrying guns gathered this week, not far from a building where President Barack Obama was talking to the public about his plans to reform U.S. healthcare.
One of them had a rifle slung over his shoulder, a handgun in a holster and bullets in his back pocket.
Last week, a man protested outside another Obama healthcare meeting with a gun strapped to his thigh.
It may be hard to believe but it wasn't illegal.
The meetings were held in parts of the U.S. that restrict concealed weapons but allow them to be carried freely if they're in plain sight.
A small number of activists make a point of exercising that right.
The right has limits. The Secret Service can bar anyone with a gun from entering the buildings where the president was speaking.
The protesters stayed far enough away to avoid trouble, though one man was arrested for trespassing and police found a gun in his car.
In both places, the protesters said they opposed the president's plans for healthcare but meant him no harm.
"An armed society is a polite society," said William Kostric. Should people be allowed to own guns? Sound off below
Lately, the United States has been anything but polite.
The healthcare reform plan has sparked the angriest opposition that the president has encountered since taking office.
Most of the ire has been directed at lawmakers, who have also been meeting voters to discuss the plan. They've been interrupted, insulted and threatened.
Obama doesn't attend those meetings but he's hardly overlooked. A protester outside one meeting held up a sign saying "Death to Obama" and "Death to Michelle and her two stupid kids."
Is the president in danger?
When it comes to armed protesters standing outside a building while the president is inside, a Secret Service spokesman told CNN "of course not."
But Americans remember the assassinations of presidents from Abraham Lincoln to John Kennedy and the attack that wounded Ronald Reagan.
Now, Barack Obama's trips across the country to talk about health may be attracting people with guns.
It's an odd and unsettling thing.