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The critics agreed: Lippmann’s book was brilliant. At least, until the final chapter, in which Lippmann offered gauzy and unpersuasive hopes that mankind’s better angels would rise up and banish “hatred, intolerance, suspicion, bigotry, secrecy, fear and lying” from the public square. The conclusion, H.L Mencken said, collapsed into “mystical gurgle.”

But Greenberg was sympathetic. “Lippmann’s experience will be familiar to almost anyone who has written a book aspiring to analyze a social or political problem. Practically every example of that genre, no matter how shrewd or rich its survey of the question at hand, finishes with an obligatory prescription that is utopian, banal, unhelpful or out of tune with the rest of the book.”

President Obama’s address from Osawatomie, Kan., also had a last-chapter problem.

After eloquently diagnosing the way the economy has failed the middle class while enriching and empowering the top 1 percent, it ended by calling on Congress to extend and expand the payroll tax cut, raise the tax rate on income over $250,000 to 39.5 percent from 35 percent and green-light more infrastructure spending. The speech got right to the heart of our economic problems. The solutions got right to the capillaries.

Some commentators have responded by asking Obama to offer bigger, bolder policies. But the White House doesn’t have some folder marked “Awesomer Economic Agenda” tucked away in Gene Sperling’s old office. The economic plans the team has proposed are, given the composition of Congress and the realities of public opinion, the plans it supports.

So rather than reupholstering its economic agenda, the White House should take its cue from the speech it was honoring — the address Theodore Roosevelt delivered in Osawatomie a century before.

In that speech, Roosevelt argued that extreme concentrations of wealth didn’t just pose a threat to the incomes of the middle class or some abstract sense of fairness. They threatened the very workings of the political system. The richer the 1 percent became, the more political representation they could buy. The more political representation they could buy, the richer they could become.

And that inspired the speech in Kansas. “Every special interest is entitled to justice, but not one is entitled to a vote in Congress, to a voice on the bench, or to representation in any public office,” Roosevelt thundered. “The Constitution guarantees protection to property, and we must make that promise good. But it does not give the right of suffrage to any corporation.”

Today, of course, the corporation is legally considered a person, and the Supreme Court has granted it the constitutional right to spend an unlimited amount of money to influence elections — and to do so anonymously. Here’s Roosevelt again: “Corporate expenditures for political purposes, and especially such expenditures by public-service corporations, have supplied one of the principal sources of corruption in our political affairs.”

In 2008, Obama won the presidency by promising to change Washington — to reduce the power of special interests, of corporations, of lobbyists. But the fall of Lehman Brothers preempted that agenda. Rather than changing Washington, Obama has spent the past three years trying to stabilize the economy. And, with the Citizens United decision, the Supreme Court changed Washington — but for the worse.

That gives Obama an opportunity to pivot to the agenda that got him elected. He can argue, fairly and accurately, that he had to spend much of his term managing such policies as TARP and the auto bailout. With the economy slowly coming around, now is the time to turn back to his original project of change. After four years of managing a crisis wrought by an overly powerful financial elite and a broken political system, the case for reforms that wring the money out of politics and attack the core causes of congressional dysfunction is stronger than ever.

Of course, such an agenda would still leave Obama with a last-chapter problem. Changing Washington would help clear the way for the policies that would address the nation’s economic problems — policies that, in some cases, will need to be passed, and even thought up, by Obama’s successors. It took decades to get America into this mess. It will take much more than a single president to get us out.

And the truth is, I’m left with a last-chapter problem, too. It’s all well and good to call for reforms to clean up and modernize the political system, but such things are easier said than done. The Supreme Court presents a significant challenge to all but the most modest of campaign-finance reforms, and though the wanton deployment of the filibuster has rendered both parties nearly incapable of governing, there’s little congressional support for reforms that would allow majorities to actually pass the policies they’ve promised voters.

And even if the magic wand could be waved and the blockages of Washington lifted, we would still be far from solving our economic problems. Think tanks fairly burst with good ideas for changing the tax code and improving the health-care system and rebuilding our infrastructure. But when it comes to explaining why, exactly, median incomes have stagnated for decades and what, exactly, we can do about it, the conversation gets a little quieter. We’re much better at solving policy problems than we are at solving economic problems.

But to get to the right answers, you must first ask the right questions. “In the end,” wrote Greenberg, “most authors have themselves to blame. Having immersed themselves in a subject, almost all succumb to the hubristic idea that they can find new and unique ideas for solving intractable problems. They rarely do, and even works that do usher in specific reforms or broad social transformations — from ‘The Jungle’ to ‘The Feminine Mystique’ — do so by raising awareness about an issue, not by providing ready-to-go blueprints.”