For decades, Democrats and Republicans fought over who owns the American flag. Now they're fighting over who owns the Constitution.

The flag debates began during the Vietnam era, when leftist radicals made the fatal error of burning it. For decades since, non-suicidal liberals have tried to undo the damage. Demeaningly, and somewhat unfairly, they are forever having to prove their fealty to the flag.

Amazingly, though, some still couldn't get it quite right. During the last presidential campaign, candidate Barack Obama, asked why he was not wearing a flag pin, answered that it represented "a substitute" for "true patriotism." Bad move. Months later, Obama quietly beat a retreat and returned to wearing the flag on his lapel. He does so still.

Today, the issue is the Constitution. It's a healthier debate, because flags are pure symbolism and therefore more likely to evoke pure emotion and ad hominem argument. The Constitution, on the other hand, is a document that speaks. It defines concretely the nature of our social contract. Nothing in our public life is more substantive.

Americans are in the midst of a great national debate over the power, scope, and reach of the government established by that document. The debate was sparked by the current administration's bold push for government expansion - a massive fiscal stimulus, Obamacare, financial regulation, and various attempts at controlling the energy economy. This engendered a popular reaction, identified with the tea-party movement but in reality far more widespread, calling for a more restrictive vision of government, more consistent with the founders' intent.

Call it constitutionalism. In essence, constitutionalism is the intellectual counterpart and spiritual progeny of the "originalism" movement in jurisprudence. Judicial "originalists" insist that legal interpretation be bound by the text of the Constitution as understood by those who wrote it and their contemporaries. Originalism has grown to become the major challenge to the liberal "living Constitution" school, in which high courts channel the spirit of the age, free to create new constitutional principles accordingly.

What originalism is to jurisprudence, constitutionalism is to governance: a call for restraint rooted in constitutional text. Constitutionalism as a political philosophy represents a reformed, self-regulating conservatism that bases its call for minimalist government - for reining in presidents and legislatures - in the Constitution.

Hence that highly symbolic moment on Thursday when the 112th House of Representatives opened with a reading of the Constitution. Remarkably, this had never been done before - perhaps because it had never been so needed. The reading reflected the feeling, expressed powerfully in the last election, that we had moved far, especially in the past two years, from a government limited by its enumerated powers to a government constrained only by its perception of social need.

The most galvanizing example of this expansive shift was, of course, the Democrats' health-care reform, which will revolutionize one-sixth of the economy and levy a fine on anyone who does not enter into a private contract with a health-insurance company. Whatever its merits as policy, there is no doubting its seriousness as constitutional precedent: If Congress can impose such a mandate, is there anything that Congress may not impose on the individual?

The new Republican House will henceforth require, in writing, constitutional grounding for every bill submitted - a fine idea, although I suspect 90 percent of them will simply make a ritual appeal to the "general welfare" clause. Nonetheless, anything that reminds members of Congress that they are not untethered free agents is salutary.

But still mostly symbolic. The real test of the Republicans' newfound constitutionalism will come in legislating. Will they really cut government spending? Will they really roll back regulations? Earmarks are nothing; do the Republicans have the courage to go after entitlements as well?

In the interim, the cynics had best tread carefully. Some liberals are already disdaining constitutionalism, denigrating the document's relevance, and sneering at its recitation. They sneer at their peril. In focusing on a majestic document that bears study and recitation, the conservatism of the Obama era has found not just a symbol, but an anchor.

Constitutionalism as a guiding political tendency will require careful development, as did jurisprudential originalism. But its wide appeal and philosophical depth make it a promising first step to a conservative future.

Charles Krauthammer is a Washington

Post columnist. He can be reached at letters@charleskrauthammer.com.