I don't put much stock in politicians, so I've only twice donated to political campaigns. In 2006, I tossed a few dollars at the Democrat running for Senate against the loathsome Rick Santorum. It could have been a three-headed goat, for all I cared, but Wikipedia says it was Bob Casey. (You're welcome, Bob.) And late in 2007, I gave $50 to Ron Paul. I was working at the time for the Cato Institute, a libertarian think tank, but it wasn't that I had any plans on voting for him. I liked the congressman’s anti-war rants in the 2007 GOP debates, not least because they made Rudy Giuliani delightfully apoplectic. So I chipped in.

Paul’s candidacy that year, as we all know, didn’t lead him to the White House or anywhere close. But he evidently wasn’t discouraged. Four years later, Paul is not only back on the campaign trail, he's doing better than ever in the polls. And I'll admit I still vibrate happily to his indignant disquisitions on foreign policy. (Why shouldn't Iran have nukes!) I just can't get myself to regret that $50 when I hear him say "blowback" in the vicinity of Mitt Romney.

Yet it irks me that, as far as most Americans are concerned, Ron Paul is the alpha and omega of the libertarian creed. If you were an evil genius determined to promote the idea that libertarianism is a morally dubious ideology of privilege poorly disguised as a doctrine of liberation, you'd be hard pressed to improve on Ron Paul.

Much of Paul's appeal comes from the impression he conveys of principled ideological coherence. Other Republican presidential aspirants are transparently pandering grab-bags of incoherent compromise. Ron Paul presents himself as a man of conviction devoted to liberty, plain and simple, who follows logic's lead and tells it plain. The problem is, often he’s not.

According to Paul's brand of libertarianism the inviolability of private property is the greater part of liberty. And Paul is crystal-clear about the policy implications of his philosophical convictions about property rights. As Paul writes in his 2009 book Liberty: A Manifesto, the income tax implies that "the government owns you, and graciously allows you to keep whatever percentage of the fruits of your labor it chooses." To Paul, the policy upshot is evident: "What we should work toward ... is abolishing the income tax and replacing it not with a national sales tax, but with nothing." Whatever you think of this, you can't accuse Paul of dancing around the issue. However, Paul is not so dogged in consistently applying his principles in other domains.