So.

A man who's never committed a violent crime or been legally adjudicated as mentally defective passes the federally-mandated background check, buys a 9mm Glock (arguably the most common handgun in the United States, both among police and private citizens), and shoots a politician.

His motivation? Frankly, it's not clear that he had a coherent one. He believed that the Bush administration engineered the September 11 attacks. He believed a shadowy cabal was building a New World Order. He wanted to return the US to a silver and gold standard. If you take a signature issue of any group you dislike, a little digging would probably find it in the shooter's worldview. And predictably, there's been a land rush by all of the American political parasites to brand him as a fellow traveler with the enemy.

A sentiment that I've seen stated explicitly in some coverage and is implicit in almost all of it is the idea that there's no place in our society for political violence. Politicians have already suggested gun control and laws criminalizing speech that might advocate harm to government officials, because obviously we need to take legal steps to minimize the potential for political violence. It's such a matter of common sense that most people don't even feel the need to say it out loud. But honestly, this is one of those truisms that doesn't stand up to analysis, and frankly, when earnestly believed it's disturbingly misguided.

This country was founded in a huge act of political violence. We wouldn't exist as a nation without the work of tens of thousands of men who thought it was acceptable, in dire extremity, to shoot government employees.

Now, there are some who think that voting has made physical resistance obsolete, and it's a happy truth that democracy has moved the threshold of "dire extremity" pretty dramatically. But it only takes a moment's thought to establish the principle: what would the majority have to consent to to justify the minority getting shooty? Exterminating Jews? Reestablishing slavery? Suspending the Bill of Rights? Imprisoning enemies of the state? Deporting "undesirable" races? Declaring open-ended martial law? Holding and torturing suspected terrorists without trial or charge? Compiling intelligence on the political affiliations of Americans who've committed no crimes? A routine and casual disregard for the Constitutional restraints on Congressional power?

We'll all draw the exact line in different places. And I think everybody reading this will agree that a lone loony shooting a random politician is solidly in the illegitimate end of the political violence spectrum, but it is a spectrum. There is legitimate political violence, and the people's capacity to commit it is an essential component of a free society, and anybody who truly believes otherwise is deserving only of pity. It's a very, very sad human being who can think of nothing worth fighting to protect. "A people who mean to continue free," John Randolph said in 1790, "must be prepared to meet danger in person."

When people start advocating restrictions on civil rights in the interest of protecting politicians, we have to always remember that the First Amendment was written explicitly to protect inflammatory political rhetoric. And the Second Amendment was specifically intended to result in a populace well equipped to do political violence. When we've made the moral decision that the ability to angrily denounce government and to forcibly tell it "no; no farther" are fundamental human rights, we knowingly sacrifice the ability to deny guns and inspiration to people like the Tucson shooter. In such a nation, it's a certainty that tragedies like this one will happen sometimes. It's a trade we make because we must. It's awful, but it beats the hell out of the alternative.