Many people think political philosophy comes in two varieties, liberal or conservative. The former values social freedoms while seeking government control over capitalist acts between consenting adults (in Robert Nozick’s wonderful phrase). Conservatives defend economic freedom but not other acts between consenting adults. As a philosophy that seeks both social and economic liberty, libertarianism has sometimes seemed at the margins of American politics. A recent poll throws doubt on that assumption.

The Pew Research Center measured political ideology based on six questions from one of their 2004 surveys. Three of the questions concerned economic liberty, the others social freedoms. Liberals scored high on social freedoms, conservatives on economic liberty, and populists had little regard for either. Libertarians, as you might expect, consistently supported liberty in both dimensions.

Pew estimates that 9 percent of Americans are libertarians. That might seem low until you realize that 18 percent are liberal, 16 percent populist, and 15 percent conservative. Pew calls the rest of the nation “ambivalents” who have no firm ideological outlook. As Scott Keeter, the author of the Pew study, concludes “libertarians, though the smallest of the ideological groups, represent a substantial percentage of the population.”

A lot of what Pew discovered about libertarians may not surprise you. They are more likely than the rest of the population to have a college degree, to be in the highest income category, and to come from the West. On the issues, libertarians are more likely to think homosexuality should be accepted, to favor stem-cell research, to believe businesses make a fair profit, and to find free trade good for the nation.

But some of Pew’s other findings about libertarians are more unexpected, at least to me. Libertarians are 50 percent more likely to declare themselves “secular” than the general population. Still, only about 12 percent of the libertarians surveyed identified themselves this way. Libertarians are also more likely than the general population to identify as a “white Catholic.” Finally, almost two-thirds of the libertarians said they go to church at least once a month. That’s a little less than the general population, but a lot more than I would have guessed.

Half of the libertarians identified with or leaned toward the Republican party. At the same time, 41 percent affiliated themselves with the Democrats. Sen. Kerry got 40 percent of the libertarian vote in 2004. President Bush did better among libertarians than you might expect given the party identification numbers. Bush got 57 percent of libertarian vote last time. But as they say, “if the election were held today….”

I have saved the best for last. One-third of Pew’s libertarians are between 18 and 29 years of age. Libertarians are thus fifty percent more likely to be found among the young than in the population as a whole. They are also much more likely to be found among the youngest cohort than are conservatives or populists.

So the present may seem bleak for libertarians. But just wait. Help is on the way.