The health reform debate has sparked numerous questions about the cost and scope of government involvement in health care. But few members of Congress have bothered to ask what the Constitution has to say on the topic -- even though they are sworn to uphold the principles articulated in that document.

One reporter dared to ask House Speaker Nancy Pelosi on Oct. 22 where the Constitution grants Congress authority to require individuals to buy health insurance. An obviously annoyed Speaker Pelosi replied: "Are you serious? Are you serious?"

It is a very serious matter indeed. The speaker's vexed response reveals the extent to which many of America's intellectual, cultural and political elites have blithely abandoned the principles of America's founding. They see these principles as outdated if not outright defective, with little or no relevance to modern governance.

How -- and why -- did this come to be? It all began 100 years ago as an intellectual project involving mostly of academics and writers. It evolved into a popular reform effort under the banner of "progressivism." Today, it's the foundation of modern liberalism.

It's important to understand how deeply the progressive movement has transformed our politics and society -- and where, if left unchecked, it will take us.

Progressive thinkers sought to "re-found" America according to ideas alien to Washington, Adams, Jefferson, Hamilton and Madison. Repudiating the Founders' belief in the existence of self-evident truths, Progressives asserted that there are no truths, only relative values. Similarly, they claimed, man enjoys no permanent rights endowed by God, only changing rights held at the indulgence of government. Thus, lacking eternal truths and rights, Americans must be governed by a "living" Constitution, one that endlessly "evolves" and "grows" with the times.

The Progressive Movement -- first under a Republican president, Theodore Roosevelt, and then a Democratic one, Woodrow Wilson -- set forth the platform of modern American liberalism: Progress means a form of government able to engineer a better society, assuring equal outcomes and redistributing wealth. A distant, patronizing welfare state regulates more and more of our economy, politics and society.

President Franklin Roosevelt's New Deal and President Lyndon Johnson's Great Society were grand steps toward achieving the progressive platform.

Today we see a new, more aggressive move in this direction. Progressives insist that the modern world is so complex and problematic, an activist government is required to manage political life and human affairs.

This new liberalism seeks to transform America's constitutional structure of limited government into an increasingly powerful, centralized government focused on social reform. The rise of the modern administrative state, the growth of bureaucracy at every level and the host of benefits the public has come to expect from government all undercut and pervert the American idea of self-government.

The result: America is moving ever further away from the nation's original principles and constitutional design. No, progressive ideas have not completely won the day. And in important ways, the progressive liberals have had to adapt to realities defined by the American political tradition.

Even so, the dominance of progressive arguments -- in our schools and in the public square, as well as in our politics -- has significantly weakened the very foundations of American constitutionalism and limited government. That, of course, makes it all the more necessary to defend and recover the ideas of the Founders.

To flourish in the 21st century, America doesn't need to redefine or remake itself by rejecting its core principles and in favor of more stylish beliefs. Rather what's needed is a great renewal of the foundational principles that are the true roots of American greatness.

We must look to the principles of the American founding. They provide our philosophical grounding, practical wisdom and limitless spirit of self-government and independence.

This isn't merely a matter of historical curiosity. In a world of moral confusion, of arbitrary and unlimited government, the founding is our best access to permanent truths. It's our best ground from which to repulse the whole progressive project to remake America.

So yes, Mrs. Pelosi, we're serious.

Matthew Spalding, Ph.D., is director of the Kenneth B. Simon Center for American Studies at the Heritage Foundation and the author of We Still Hold These Truths: Rediscovering Our Principles, Reclaiming Our