For libertarians, Christian conservative pro-lifer Jim DeMint was the best thing to come through the Senate in decades. DeMint, quitting early to run the conservative Heritage Foundation, embodied an underappreciated fact of life in Washington: The politicians who most consistently defend economic liberty are the cultural conservatives.

The National Taxpayers Union gave DeMint a 93 percent rating last year, putting him third out of 100. DeMint scored 100 percent from the Club for Growth, whose sole focus is economic conservatism.

Until last year, DeMint was the only senator with a lifetime 100 percent from the Club for Growth. He still has a perfect record, but now he has company: Rand Paul, Mike Lee and Ron Johnson -- all pro-life conservative freshmen derided as "Jim DeMint disciples" by the likes of lobbyist Trent Lott.

Many libertarians realize that DeMint has been one of their best allies in the U.S. Senate. Nick Gillespie and Matt Welch, editors of Reason magazine, are libertarians with social liberal tendencies. When they interviewed him in May, they pointed out how much this Christian social conservative had to offer their ilk.

DeMint's 2012 book, "Now or Never," is a fiscal conservative book from cover to cover. Who wrote the foreword? Rand Paul, probably the most libertarian senator in a generation -- and Paul probably wouldn't be in the Senate if DeMint hadn't backed him in his 2010 primary. And DeMint boosts Rand's father, libertarian hero Ron Paul. Gillespie wrote last week: "DeMint is a social con's social con, but ... amazingly, he praised Rep. Ron Paul's libertarian influence on the GOP base."

When DeMint departs from Republican orthodoxy, it's in the libertarian direction. He broke with his party just after Thanksgiving, when he voted to bar indefinite detention of Americans suspected of terrorism. Then he voted against the National Defense Authorization Act, a bugbear of civil libertarians.

DeMint was an early and vocal opponent of the industry-backed Stop Online Piracy Act, which galvanized civil libertarians on the Left and Right last year.

On military spending, DeMint also parts ways with his party leadership, calling for cuts. "Not just the waste," he said in May. "We do need to rethink the money we spend on military and defense. ... Frankly, some of our spending is politically driven because a particular defense system or ship is built in a certain congressional district or state."

DeMint upsets some libertarians because of his culturally conservative views. "Good riddance, Mr. DeMint," wrote libertarian blogger Andrew Kirell at the website Mediaite, upon the news of DeMint's early exit.

DeMint is pro-life. So is Ron Paul, who explains that the most basic function of government is to protect the vulnerable from violence.

Also, the big-government side in today's abortion battles is the "pro-choicers": The Senate hasn't tried to curb abortion much in recent years, instead, the fight is over how big the federal subsidies should be for abortion giant Planned Parenthood. Just as with the contraception mandate, the socially conservative position here is "get Washington out of this."

DeMint opposes gay marriage, but again, the U.S. Senate hasn't had much to say on the issue.

DeMint did vote against libertarian principles on some prominent issues, such as immigration. But when DeMint offended libertarians, it was mostly with his words. In a 2004 debate, DeMint said he didn't think open lesbians or women who are pregnant out of wedlock should be teaching. But it never mattered what DeMint thought about who should and who shouldn't be teaching -- in part, because he believes in federalism and he doesn't want Washington meddling in education.

DeMint upset libertarians when he told Fox in 2010, "You can't be a fiscal conservative unless you're also a social conservative."

DeMint's wording was very poor, and this is a gross overstatement. But had he been more careful, he would have had a good point.

DeMint and others could make deeper philosophical arguments about family, church and community as counterweights to state power, but there are also the basic facts on the ground: The best fiscal conservatives in politics are all social conservatives. Look at the Club for Growth scorecard again. All the most fiscally conservative senators are pro-life. You have to go down to No. 27 in the Club's rankings -- Mark Kirk -- to find a pro-choicer.

Self-described "fiscal conservatives and social moderates" almost never end up being both. Most end up embracing taxes, regulation and spending like Mark Kirk, with a Club for Growth lifetime score of 52 percent. The rest become pro-lifers like Pat Toomey.

Traditional morality and limited government aren't enemies. They're friends. DeMint proved that, and he left behind heirs who will continue to do so.

Timothy P.Carney, The Examiner's senior political columnist, can be contacted at tcarney@washingtonexaminer.com. His column appears Monday and Thursday, and his stories and blog posts appear on washingtonexaminer.com.