The defeat of House Majority Leader Eric Cantor by economist David Brat in a Virginia congressional primary generated lots of headlines about grass-roots insurgency in the Republican Party.

Former Minnesota governor Tim Pawlenty, a mild-mannered moderate, told journalists that “the new energy in the Republican Party is the libertarian strain in the party. It has matched and in my view exceeded the power and momentum and volume of the tea party.” Fire-breathing South Carolina conservative Katon Dawson complained: “There is a loud libertarian faction. Libertarianism has moved into the Republican Party and is trying to hijack it.” A strange complaint from a guy who was part of the Southern conservative influx into the Republican Party in the 1960s.

The rise of libertarianism in the political world is something I’d noticed before this recent election. Throughout 2012 and 2013 newspapers had run headlines such as “Rand Paul and the rise of the libertarian Republican,” “Libertarians’ rise has the GOP boiling,” “Libertarians, tech titans poke old-school GOPers,” “Americans are tilting more libertarian on foreign policy,” “Libertarian Populism and Its Critics,” “The tide is rising for America’s libertarians,” and my favorite — on page 2 of the Washington Post — “Libertarianism is hot.”

As one indication of the increasing attention paid to libertarians in the media, in 2013 the Washington Post had 27 headlines with the words “libertarian” or “libertarianism.” In 2003 there were two.

Not all the action is in the Republican Party. Under the headline “Southern-Fried Freedom Lovers Propel Libertarian Candidates,” the Daily Beast reported in June on Libertarian Party candidates in Florida, Georgia, and North Carolina bumping 10 percent in early polls. No doubt they were inspired by Robert Sarvis’s 6.6 percent in the 2013 Virginia gubernatorial race.

Sometimes I wonder what politicians and pundits mean when they talk about libertarians in the Republican grass roots. I doubt there are millions of consistent advocates of individual liberty, limited government, free markets, and peace. I fear they just mean “conservatives who talk about principles,” or maybe even “angry conservatives.”

But I hope I’m wrong about that. David Kirby, who spearheaded the “libertarian vote” studies that Cato has published over the past decade, found the number of libertarians in the Republican electorate rising from 15 percent in 2002 to 34 percent, based on two questions in the annual Gallup Poll Governance Survey about “government trying to do too many things” and whether “government should promote traditional values.” A Freedomworks survey found that 78 percent of Republicans and GOP-leaning independents self-identify as fiscally conservative and socially moderate.

I wrote a whole book on the definition of libertarianism. But for political purposes I’d say that what makes a voter, activist, or candidate a libertarian would be a commitment to economic freedom, personal freedom, civil liberties, and nonintervention. Given the exigencies of politics, I might settle for three out of four. Republican candidates and elected officials may even be perceived as “libertarian-ish” if they’re strongly committed to free markets and not much interested in conservative social issues.

As I’ve written at Cato’s blog, Cato at Liberty, genuine swing voters tend to hold libertarian views. A Washington Post-ABC News poll in 2012 found that 64 percent supported “smaller government with fewer services,” and 63 percent favored gay marriage (compared with 53 percent of the total electorate then). That’s the sort of understanding that led to another of those recent headlines: “Libertarian swing vote in play.”

Libertarian ideas are spreading, both among intellectuals and more broadly among voters. Voters with libertarian views are becoming more aware of their impact. Politicians and journalists are starting to notice the libertarian vote. Libertarian views are coming under more attack, from conservative politicians, liberal magazines, and more. This is all part of what we might call the mainstreaming of libertarianism.

Rep. Ron Paul and Sen. Rand Paul have helped make libertarianism a more visible part of our politics, but we shouldn’t forget the important role played by George W. Bush, the Federal Reserve, Barack Obama, the IRS, the NSA, and the VA.

We’ll also take some credit here at Cato. One close observer of the Cato Institute and the national debate said to me recently, “Cato’s job is to describe and defend libertarianism with credible scholarship so that policymakers, journalists, and intelligent lay people recognize libertarianism as a respectable intellectual position worthy of attention. Cato has been remarkably successful at carrying out its core function.”

Of course, we hope that the impact of libertarian ideas is still on the rise, and we’ll continue to work to make that the case.