The Republican Party’s internal divisions over Syria have broken along familiar lines. Establishment conservatives such as Sens. John McCain of Arizona, Lindsey Graham of South Carolina, and Speaker John A. Boehner of Ohio plan to defend the president’s red line abroad. The next generation of Republicans, including Sens. Rand Paul of Kentucky, Mike Lee of Utah, and Ted Cruz of Texas, and Reps. Justin Amash of Michigan and Thomas Massie of Kentucky are worrying more about red ink here at home.

The same red line is drawn in one congressional policy battle after another — from Syria to the use of drones and National Security Agency surveillance to efforts to defund Obamacare, cut spending and stop debt ceiling increases. It’s an uphill battle for the liberty-minded. As Paul reflected in the press, “We’re losing, on a good day, 70/30 among the Republicans. But we win every day among the grass roots, probably 80/20, 90/10.”

A new analysis of Republican voters shows that Paul’s grass-roots estimate may not be off by very much. His foreign policy skepticism has actually become a majority opinion among Republicans. Recent polling conducted for FreedomWorks by the Polling Company Inc. found that 51 percent think the United States should not “take the leading role among all other countries in the world in trying to solve international conflicts,” compared with 39 percent who say the United States should.

More broadly, the views that Paul and many of his colleagues espouse on the proper size and role of government reflect the growing segment of the Republican Party, where small-L libertarian sentiments are at the highest level since 2000.

In fact, 41 percent of Republican voters hold limited-government views. (American National Election Studies found 26 percent in 2000; Gallup found just 15 percent in 2002.) Furthermore, 68 percent now agree with the libertarian view that “individuals should be free to do as they like as long as they don’t hurt others, and that the government should keep out of people’s day-to-day lives.” The old stigma of the libertarian label is eroding; 42 percent of Republicans had a favorable view of the term in the new poll.

These voters can be identified as libertarian based on their fiscally conservative but socially moderate views, even if the word libertarian may be unfamiliar to them.

Civil liberties and spending issues are scrambling the old foundations of the Republican Party. In the 1980s, Ronald Reagan called the Republican coalition a three-legged stool of individual freedom, traditional values and defense. Today, it’s a lopsided stool. Forty percent of Republican voters said they are most interested in promoting “individual freedom through lower taxes and reducing the size and scope of government,” compared with 27 percent for “traditional values” and 18 percent for “strong national defense.”

The message for Republicans heading into the 2014 primaries is to draw their red lines here at home on the fiscal issues. That’s why FreedomWorks decided to key vote “no” on the congressional authorization of force in Syria. The costs of military action are rarely limited, and Congress has an obligation to put America’s international credit ahead of President Barack Obama’s rhetorical credibility.

As with the defeat of the first Troubled Asset Relief Program bailout attempt in 2008, the grass roots are uniting behind lawmakers willing to take a principled stand against their tone-deaf colleagues. On all issues, from Syria to the national debt, Republican incumbents will have to stake out and stick to a liberty-minded position if they hope to win primaries in 2014.

Today, 67 percent of Republican voters want their elected officials to keep their promises and stick to principles rather than “compromise in a bipartisan way to get things done.” And voters aren’t buying electability arguments from a GOP establishment that insists on running unprincipled moderates on the Republican ticket. Fifty-five percent of Republican voters favored a hypothetical candidate with stronger principles, compared with 34 percent who opted for a candidate deemed more likely to win.

Republican primary voters seem to have grown weary of party leaders and consultants who declare who can win before a single vote is cast, and it’s stoking a libertarian revival in the Republican ranks. We are drawing a red line of our own. As primaries play out in 2014 and beyond, it’s only a matter of time before the Republican caucus catches up to the electoral reality.

David Kirby is vice president of opinion research and data analysis at FreedomWorks.