How can Kerry persuade moderates to throw out Bush? By turning the president's message against him. Bush is steady and principled. He believes money is better spent by individuals than by the government.

He believes the United States should assert its strength in the world. He believes public policy should respect religious faith. Most Americans share these principles and think Bush is sincere about them. The problem Bush has demonstrated in office is that he has no idea how to apply his principles in a changing world. He's a big-picture guy who can't do the job.

From foreign to economic to social policy, Bush's record is a lesson in the limits and perils of conviction. He's too confident to consult a map. He's too strong to heed warnings and too steady to turn the wheel when the road bends. He's too certain to admit error, even after plowing through ditches and telephone poles. He's too preoccupied with principle to understand that principle isn't enough. Watching the stars instead of the road, he has wrecked the budget and the war on terror. Now he's heading for the Constitution. It's time to pull him over and take away the keys.

Bush was right to go to war against the terrorists who struck us on 9/11. He was right to demand the overdue use of force against the scofflaw Iraqi regime. But he couldn't tell the difference between the two threats. He figured that since both Saddam Hussein and Osama Bin Laden were evil, they had to be connected. Saddam must have helped orchestrate the 9/11 attacks. He must have built weapons of mass destruction to sell to al-Qaida.

In recent months, congressional hearings and document leaks have unearthed a disturbing history. Again and again in 2001 and 2002, U.S. intelligence agencies sent signals that Bush was wrong. The FBI and CIA debunked putative links between Iraq and al-Qaida. The CIA rejected the claim that Iraq had tried to buy uranium from Africa. In its National Intelligence Estimate, the CIA calculated that it could take Saddam up to five years to make a nuclear weapon and that he would transfer WMD to terrorists only if he were invaded. The Defense Intelligence Agency advised the administration that there was "no reliable information on whether Iraq is producing or stockpiling chemical weapons." The Air Force disputed the suggestion that Iraq had developed aerial drones capable of delivering chemical or biological toxins. Analysts questioned whether the White House was right that Saddam's aluminum tubes were designed for building nukes, or that two trucks the White House found suspicious were designed for making biological weapons.

Bush ignored every one of these warnings. They couldn't be true, because they didn't fit his theory. He couldn't stand the complexity of the facts or the ambiguity of intelligence. "Until we get rid of Saddam Hussein, we won't get rid of uncertainty," he told aides in November 2002. Four months later, on the eve of his invasion of Iraq, he declared, "Intelligence gathered by this and other governments leaves no doubt that the Iraq regime continues to possess and conceal some of the most lethal weapons ever devised." After the war, when Diane Sawyer asked Bush about the discrepancy between his ironclad statements and the more tentative weapons estimates provided by U.S. intelligence, he replied, "What's the difference?"

That's Bush all over: Certainty. No doubt. No difference. But it makes a difference to Britain, France, and Mexico, which no longer trust our requests, based on U.S. intelligence, to cancel flights to the United States. And it makes a difference to China, which refuses to accept our report, based on U.S. intelligence, that North Korea is operating a highly enriched uranium program. Bush's overconfidence - reflected in a series of exaggerations wholly unnecessary to the punishment of Saddam for his noncompliance with U.N. inspections - has trashed our credibility and cost us vital help with other terrorist and WMD-related threats.

Bush was right to propose tax cuts in 1999. The economy was booming. The surplus was ballooning. Liberals were itching to spend the money on new programs, despite Bill Clinton's promises to pay down the national debt. Bush wanted to get the money out of Washington before that happened. That's why, under his plan, the size of the tax cut was to grow from year to year. The point was to keep the surplus from piling up, refunding more and more money as it poured in from a growing economy. That's also why Bush cut taxes across the board instead of targeting middle-class families who would spend the money immediately. He wasn't trying to stimulate the economy. He was trying to give the money back to the people who had paid it in, which meant largely the rich.

Then everything changed. The stock market tanked, and the economy slowed. Sept. 11 shook the nation's confidence and drastically altered military budget projections. Bush didn't need to drain a surplus anymore. He needed to fund national defense and stimulate the economy. He needed to get rid of his back-loaded across-the-board tax cut and replace it ... with front-loaded tax cuts aimed at consumers. Instead, Bush claimed that his original tax-cut elixir was just as good for the new malady as for the old one. The deficit exploded, the economy failed to recover the jobs it had lost, and much of the country remained unprotected from terrorism. The world changed, but Bush couldn't.

When Bush banned federal funding of research on new embryonic stem cell lines, he said sufficient research could proceed because "more than 60" existing cell lines would still be eligible for grants. The true number turned out to be less than half that, but Bush didn't budge. Last fall, in the name of human life, he signed into law a bill that required any doctor performing a second-trimester abortion to cut up the fetus inside the woman instead of removing it intact. Good principle, atrocious policy. His initiative to fund faith-based social programs has been a classic liberal misadventure, adding religious mini-bureaucracies to various Cabinet departments despite a study last year that showed faith-based job training programs were no more effective, and in some ways less effective, than regular job training programs.

Now, to save the family, Bush proposes to monkey with the Constitution. Why is this necessary? Because conservative states might be forced to honor gay marriages performed in liberal states, says Bush. But didn't the Defense of Marriage Act void that requirement? Yes, Bush argues, but DOMA might be struck down. Unwilling to wait for a ruling on DOMA, Bush prefers to circumvent the court system and local democracy by reopening the nation's founding document. He seeks to impose a permanent federal definition of marriage on "any state or city," regardless of what the voters in Boston or San Francisco want.

President Bush. Strength and confidence. Steady leadership in times of change. He knows exactly where he wants to lead this country. And he won't let facts, circumstances, or the Constitution get in his way.