David Brooks’s critique of a Wall Street Journal opinion piece by Arthur Brooks and Congressman Paul Ryan served its intended purpose. It’s gotten the right people talking, and thinking, and that’s as it should be when those currently out of power have a very real shot at participating in governing again.

The back and forth began with Arthur Brooks and Representative Ryan emphasizing the importance of the political moment. After years of elected officials passing laws that have piled new federal programs and commitments on top of the ones created by their predecessors, we now find ourselves with a sprawling federal apparatus that is stifling private economic initiative and bankrupting the country. It is also a powerful, self-perpetuating machine — so powerful that the long march toward ever-more activist government has continued for decades almost without interruption despite numerous efforts (think Reagan Revolution) to apply some limits to the government’s reach.

Ironically, the failure of past efforts and the election in 2008 of a chief executive and a Congress absolutely committed to accelerating the pace of federal power accumulation has sparked a national counter-reaction of such promising force and intensity that there is now renewed hope that the struggle for limited government may yet be won. That was the point of the Brooks-Ryan essay: an exhortation to voters to seize the historic, and perhaps final, opportunity before them to choose political leaders in the fast-approaching mid-term election, as well as in 2012, who are committed to changing course once and for all. This means rejecting, in a decisive way, the activism espoused by those now in power and adoption of a philosophy that puts real limits on government so that entrepreneurial capitalism can again thrive and produce the improvements in the human condition that everyone desires but which central government can never deliver.

David Brooks acknowledges the importance of delivering a decisive electoral rebuke to those currently stepping on the accelerator of the runaway federal freight train. Indeed, he takes it for granted that such a rebuke is coming. His interest is in what happens next. And here he finds the Brooks-Ryan narrative to be lacking in political subtlety. Yes, the federal government has gone beyond the boundaries of its competency — but that does not mean every federal initiative is unworthy. Brooks favors imposition of limits on government — but he fears that unreflective adherence to an anti-tax and anti-government creed will itself result in disappointment and a lost opportunity. Instead of rolling back the welfare state, Brooks fears reactionaries leading the new coalition will end up squandering their chance to make a difference by alienating independent-minded voters who want government to be competent in promoting growth and opportunity, even as it stays out of the way of job-creators in the private sector.

Of course, some of the apparent differences among these leading thinkers might be more in theory than in practice. And certainly both Arthur Brooks and Representative Ryan took exception to the implication of Brooks’s critique that they lean too heavily toward minimalist government. Both note that they support the government’s role in correcting market failure and providing a compassionate safety net.

Nonetheless, it’s useful to see this kind of debate now — even before the election outcome is a certainty. Calls for limited government in the abstract are one thing; imposition of real limits on government — that is, cuts in programs, and the rollback of regulations — is another matter entirely. Even with a robust center-right coalition controlling Congress, it will be exceedingly difficult to get agreement on specifics, as the kind of subtle difference in emphasis on display in the Brooks-Brooks-Ryan debate plays itself out among hundreds of elected leaders coming from all parts of the country. The hard truth is that every cut creates hardship for voters somewhere, and that means hardship for politicians too.

It’s also clear that the backlash against excessive government intervention in American life would not have near the strength it does were it not for the recognition that the country is careening toward a fiscal crisis. Yes, there is a healthy impulse arising to return to constitutional principles of governance. But even that wouldn’t be enough to take on entrenched federal programs were it not for the fiscal mess we are in. The federal government is running up debt like it never has before. The Obama budget plan will produce a $10 trillion budget deficit over the coming decade. That’s what motivating millions of Americans to cast their ballots for new leadership, and that’s what’s creating a new opening to consider cuts to federal programs that would never be considered if the numbers weren’t so scary.

What we are actually witnessing is the end of an economic era. The democratic capitalist countries of the West have all built welfare states of varying sizes and shapes. Europe’s is certainly much larger and more expensive than what has been built in the United States, but all are under severe strain. There is no escaping demographic reality. The aging of populations in the world’s most advanced economies will make it impossible to sustain government programs and protections at the level that exist today.

What’s needed now is an effort to harness the new national energy for reform and retrenchment to solve the nation’s entitlement problem. That will require a frank discussion with the American people about how to apply the enduring principle of limited government to the modern circumstances of a market-driven economy operating within a competitive global environment. That is the most pressing challenge in these early years of the twenty-first century.

Fortunately for us, Congressman Ryan has already given us a “Roadmap” to get the conversation started. And that’s reason enough to have a considerable amount of hope that the healthy backlash now sweeping the country will, in time, bring about the kind of reforms we need — ones that will unlock the potential of America’s private economy and thus finance a secure and stable social safety net, too.