In his 1963 book, "The Deadlock of Democracy," the historian James MacGregor Burns complained of too much fragmentation in American politics. Presidents couldn't enact their programs because it was too hard to assemble congressional majorities. Party loyalties were too weak; single-minded interest groups were too strong. To break the deadlock, Burns wanted the parties and Congress overhauled. The system should allow "the winning party to govern and the losers to oppose."

Given Americans' historical suspicion of government -- the main reason we have the system we do -- Burns's suggestions never went far. But his basic analysis remains popular because it's plausible. There's much political paralysis and much ugly legislation, the byproduct of creative coalition-building. (The recent corporate tax bill, full of dubious giveaways, is an exquisite example.) Still, I think Burns basically got it wrong. The deadlock of democracy doesn't result from the specific mechanics of governing. It stems instead from the unwillingness of our leaders to be brutally candid with the public, because doing so would be politically suicidal.

We are just completing a mean and fierce presidential campaign that affirms this dispiriting truth. While everyone has emphasized the differences between George Bush and John Kerry, what's more revealing are the similarities. Both have avoided some of the nation's most obvious problems: the coming spending explosion to pay baby boomers' retirement benefits (mainly Social Security and Medicare); the relentless advance in health costs that's squeezing wages and other government spending; the rising tide of immigration and the associated social problems; Americans' uncontrolled thirst for insecure foreign oil; and the perils of letting Iran and North Korea go nuclear.

To be sure, the candidates had positions. But these consisted mostly of appealing platitudes that said what people wanted to hear.

On energy, Kerry pledged to make us "independent" of Middle East oil; that's a practical impossibility. On Social Security and Medicare, Bush and Kerry said they won't raise eligibility ages or cut benefits, even though the costs of existing commitments will -- as a share of national income -- rise 75 percent over the next 25 years. Both had immigration proposals, but neither would actually control immigration. (Immigration needs to be controlled, not because it's bad but because without controls it won't succeed. The country can't absorb unlimited numbers of poor, unskilled immigrants.) Neither candidate would contain health spending; Kerry would simply transfer some private health costs to the federal budget.

Even on foreign policy -- where terrorism and Iraq dominated -- the campaign has had conspicuous gaps. I suspect that the next president's most fateful foreign policy decision will involve Iran's nuclear program. Can Iran be persuaded to abandon any weapons ambitions, and, if not, will the president order an attack on its nuclear facilities? Iran and North Korea came up briefly in the debates, but it was hard to tell how Bush or Kerry would handle these dangers.

At the root of all these glaring omissions is public opinion. On these issues, pleasant solutions don't exist. This is certainly true of Iran and North Korea. Anything the next president might do would carry huge risks. The choices here, as elsewhere, are between bad and worse. Bush and Kerry didn't want to offend near-retirees by saying benefits need to be cut; or Hispanics by talking realistically about immigration; or nearly 200 million licensed drivers by saying that to reduce oil demand requires a stiff gasoline tax; or most Americans by proposing tougher controls on health spending. No one wanted to hear these unappetizing policies, so Bush and Kerry didn't propose them.

You can conclude that both are dishonest. Or you can believe (as I do) that in politics honesty is bounded by practicality. Either way, the notion entertained by fanatic partisans on both sides that the "other guy" was fundamentally more deceitful is a fantasy. Whatever the differences, they were a matter of degree. You can also conclude that the omissions don't matter much. People have developed a sense of the contrasts in ideas, instincts and character between the two men. Indeed, many Americans seem satisfied with the campaign. A recent poll from the Pew Research Center found that 73 percent of respondents thought it "informative."

Up to a point, I agree. No one can absorb everything about every critical issue. We delegate detailed decisions to our elected leaders. Voters make gut judgments about which candidate's views and values coincide most with their own. Similarly, presidents inevitably face unknown circumstances and crises. Voters decide whom they trust more.

But this routine delegation works only to a point. Many pressing problems are known and something often can be done, even if the remedies may be disagreeable and incomplete. These remedies, though, cannot be deployed unless they're sanctioned by public opinion. In the United States, "public opinion stands out . . . as the great source of power, the master of servants who tremble before it" -- presidents, congressmen, governors. James Bryce, a British historian, wrote that in his classic, "The American Commonwealth" (1888). This is both the great strength and weakness of American democracy.

If the public won't abide honest discussion of clear problems -- and our leaders can't lead opinion -- then the problems simply fester. In this campaign, neither Bush nor Kerry has risen above that dilemma.

That suggests that many of our largest social problems will progressively worsen until they get so bad that we're forced to deal with them. Or they deal harshly with us. This is the true deadlock, and it may be incurable.