Is social conservatism inextricably linked to fiscal conservatism?

That’s the claim likely presidential candidate Michelle Bachmann has been making of late, including in a speech at the IMU earlier this week. And it’s one of the central internecine arguments GOP caucus-goers will have to wrestle with come February.

“Social conservatism is fiscal conservatism,” the Minnesota representative averred on Monday, undoubtedly roiling any libertarians in attendance.

For the exclusively fiscal conservatives (e.g., Gary Johnson), this is a fatuous statement: One can support gay rights and lowering taxes. Then there are the Haley Barbours of the world, who would rather inveigh against government spending than gay marriage. Sure, they say, same-sex marriage is objectionable. But fiscal issues should trump social issues.

Bachmann flatly rejects both arguments.

Instead, she asserts that “upholding life, marriage, and strong family life” is one leg of the “three-legged stool” that undergirds a strong America.

Jim DeMint, the South Carolina senator and leader of the Senate Conservative Fund, put it this way at the Values Voter Summit last year: “You cannot be a real fiscal conservative if you do not understand the value of having a culture that’s based on values.”

To social conservatives, it’s also a question of meaningful freedom — freedom unmoored from traditional (i.e., Judeo-Christian) values is picayune. (Libertarian-leaning Republicans like Johnson, in contrast, hold up unmitigated freedom as a laudable goal: Just because you’d advise your friend against smoking pot doesn’t mean there should be a law on the books forbidding its use.)

The problem is, social conservatives mistakenly equate virtue with adherence to Judeo-Christian values. Religiosity, in their mind, is the sine qua non of morality. Agnostics and atheists with a moral compass prove otherwise.

And if the only thing stopping a population from descending into drug-addled immorality were devotion to an omniscient deity, Western Europe would be a giant cesspool.

Many Western European countries have lower rates of weekly church attendance than the United States. Yet they also have lower rates of drug use. Whatever one might think of this bloc, it’s clear it hasn’t crumbled for want of a religious foundation.

The sordid picture social conservatives paint is simply untrue.

In addition, Bachmann and like-minded conservatives’ purported parsimoniousness rings hollow when it comes to the war on drugs. If she was a genuine fiscal conservative, she’d find our ineffective, wasteful policies repugnant. She’d find the amount of money we spend to lock up nonviolent offenders deplorable.

Even Obama’s drug czar, Gil Kerlikowske, told the Associated Press last year that the war on drugs has been a failure.

“In the grand scheme, it has not been successful,” he said. “Forty years later, the concern about drugs and drug problems is, if anything, magnified, intensified.”

In the end, though, my normative appraisal of Bachmann’s melding of social and fiscal conservatism matters very little. I’m a leftist — not exactly her target audience.

The more important question is, will Iowa Republicans be amenable to her ideological arguments?

In the 2008 Republican caucus, 60 percent identified themselves as born-again or evangelical Christians, and Mike Huckabee was the victor.

Huckabee is hardly the quintessential fiscal conservative — the Club for Growth derided him as “Tax Hike Mike” — but he was the most full-throated social conservative in the field. That might not be enough this time.

Both Bachmann and Huckabee have unassailable social conservative credentials and extensive name recognition, instantly catapulting them to the top of the field. But Bachmann boasts a stronger record on taxes and spending, the current mania on the right, than Huckabee.

Vociferous social conservatism can be paired with stalwart fiscal conservatism — if Republican caucus-goers so choose.