President Barack Obama's address to the nation on Iraq this week underscores the agony of his presidency, and its core political problem. Seen from the inside, the administration is an astonishing success. Obama has kept his principal promises and can take credit for achievements that eluded his Democratic predecessors.

He pledged to have all combat troops out of Iraq by the end of this month and, as Obama will remind us on Tuesday, he's accomplished just that. Congress enacted a comprehensive health-care bill and a sweeping reform of how the financial system is regulated. His rescue of the American auto industry worked, foiling predictions that he'd run GM and Chrysler as if they were arms of Chicago's Democratic machine. There are many other legislative and administrative actions that, in normal circumstances, would loom larger if these were not such exceptional—and difficult—times.

Yet the challenging nature of the times does not explain all the president's struggles. It's true that his accomplishments will have important long-term effects, even if they have not resolved the country's central concern: the continuing sluggishness of the economy.

But Obama and his party are also in a hole because the president has chosen not to engage the nation in an extended dialogue about what holds all his achievements together, or why his attitude toward government makes more sense than the scattershot conservative attacks on everything Washington might do to improve the nation's lot.

There was a revealing moment in early August when Obama told an audience at a Texas fundraiser: "We have spent the last twenty months governing. They spent the last twenty months politicking." Referring to the impending elections, he added: "Well, we can politick for three months. They've forgotten I know how to politick pretty good."

Obama's mistake is captured by that disdainful reference to "politicking." In a democracy, separating governing from "politicking" is impossible. "Politicking" is nothing less than the ongoing effort to persuade free citizens of the merits of a set of ideas, policies, and decisions. Voters feel better about politicians who put what they are doing in a compelling context. Citizens can endure setbacks as long as they believe the overall direction of the government's approach is right.

Franklin D. Roosevelt was a genius at offering such reassurances, which is why his fireside chats are the stuff of political legend. Ronald Reagan never stopped campaigning for his conservative vision because he was determined to leave behind a thriving conservative movement. Roosevelt and Reagan both changed the country's underlying philosophical assumptions.

Despite occasional forays into this realm, Obama has created the impression that he is taking things one decision at a time, without a passion for how he would like the country to look in the long run.

He and his party are often defensive when it comes to saying what they really believe: that government, well executed, is a positive good; that too much economic inequality is both dysfunctional and unjust; that capitalism has never worked without regulation and a strong dose of social insurance. They no longer dare talk about public enterprise, a phrase my friend Chris Matthews reminded me of recently, visible in our great state universities, our best public schools, our road and transit systems, and in the research and development that government finances in areas where there is no immediate profit to be made.

The Obama press office, I know, can send me speeches where he has made some of these points. But the president's efforts to lay down a consistent rationale, argument and philosophy have been sporadic. He has created a vacuum, filled by the wild charges of Glenn Beck, the disappointment of progressives who emphasize what he hasn't done, and the tired "government is always the problem" rhetoric of his mainstream conservative opponents. He has thus left himself and his Democratic allies with weak defenses against a tide of economic melancholy.

It is too late to turn this election into a triumph for the administration, but not too late to salvage his party's congressional majorities. Given dismal Democratic expectations, that would now be rated as a victory. But doing so will require Obama to think anew about what "politicking" really means, to pick more than tactical fights with his adversaries, and to lay out, without equivocation or apology, where he is trying to move the country. It's just too bad he didn't start earlier. 

(c) 2010, Washington Post Writers Group