The collapse of President Obama's agenda has sent progressives into an agitated state of finger pointing. The problems the left faces can no longer be denied — especially in the wake of Scott Brown's victory in the Massachusetts Senate race.

And yet liberals refuse to believe that the fault lies with liberalism itself. So they have latched onto another explanation: America is “ungovernable.”

There are three variations on this theme.

The first is that the American people are too stupid to govern. This charge has been made by Time magazine's Joe Klein, who, in criticizing public opposition to the president's stimulus package on Jan. 25, referred to us as a “nation of dodos.” Slate's Jacob Weisberg argued that “the biggest culprit in our current predicament” is the “childishness, ignorance, and growing incoherence of the public at large.”

Being frustrated by political setbacks is one thing; a wholesale indictment of the American people is quite another. Liberals' condemnation of the public also reveals an elitist contempt for American self-government. (During the election Mr. Weisberg wrote that if Mr. Obama lost, it could only be due to racism. “If you break the numbers down, the reason Obama isn't ahead right now is that he trails badly among one group, older white voters,” he wrote on Aug. 23, 2008. “He does so for a simple reason: the color of his skin.”)

The second variation of the “ungovernable” theme is that the fault lies with the “nihilistic” Republican Party. Newsweek's Michael Cohen summed up this view when he wrote, “Perhaps the greatest hindrance to good governance today is the Republican Party, which has adopted an agenda of pure nihilism for naked political gain.”

People who cannot distinguish between political opposition and nihilism are fundamentally unserious. Whether one agrees with the GOP or not, the conservative position on health care is rooted in a different view of the government's role in public life. This is a substantive disagreement.

The charge that the GOP has no alternatives to offer is demonstrably false. Wisconsin Rep. Paul Ryan, for one, has presented his substitute in the form of his “Patient's Choice Act” and “A Roadmap for America's Future.”

The third iteration of the America-is-ungovernable view is represented by the New York Times columnist Paul Krugman, who calls the Senate “ominously dysfunctional” and insists that the way it works is “no longer consistent with a functioning government.” Mr. Krugman blames the failure of the Obama agenda in general, and ObamaCare in particular, not on the president's unpopular policies but on long-established parliamentary procedure: the filibuster.

It's worth noting that Presidents Ronald Reagan, Bill Clinton and George W. Bush each passed significant pieces of legislation — tax cuts, welfare reform, education, terrorist surveillance and Medicare prescription drugs — with broad bipartisan support. Each won passage despite having lesser congressional majorities than does Mr. Obama, or no majorities at all.

In their eagerness to plow through their ambitious legislation, liberals are showing disregard for what James Madison called the “auxiliary precautions” of American government. The Founders set up a system of government that put a premium on slowing things down, on compromise, and on controlling passions. They intentionally made passage of massive legislation time consuming and difficult. The filibuster reflects that Madisonian spirit.

Such precautions can be overcome by a strong executive who can rally the public to his cause. But leaders championing unpopular causes find their agenda stalled and eventually defeated.

We have heard the America is ungovernable mantra before. In the fall of 1980, Lloyd Cutler, President Jimmy Carter's counsel, wrote in Foreign Affairs magazine: “one might say that under the U.S. Constitution it is not now feasible to 'form a Government.' The separation of powers between the legislative and executive branches, whatever its merits in 1793, has become a structure that almost guarantees stalemate today.”

The problem then, as now, was not with our system of government, but with our weak and liberal chief executive.

Mr. Wehner, a senior fellow at the Ethics and Public Policy Center, has worked in the administrations of Ronald Reagan, George H.W. Bush, and George W. Bush.