President Bush wasn’t on the ballot, but the election was a referendum on his divisiveness. Voters don’t like it.

ON THIS MORNING AFTER, the Republican base seems less impregnable and the genius of Karl Rove less radiant. The president and his surrogates in recent weeks tried to emulate past successes by calling Democrats tax-raising, gay-marriage-loving, terrorist-appeasing clones of John Kerry. But their dog-eared playbook -- bequeathed by Lee Atwater to “the architect� Rove -- failed them. The center still matters.

So George W. Bush, the “divided we win� president, emerges as the day’s biggest loser.

Midterm elections are always perilous for presidents, and this year’s vote amounted to a cost-free referendum on Bush’s failing occupation of Iraq. It was cost free because the midterm provided voters with an opportunity to express their displeasure with the war without actually handing over control of national security to Democrats -- a prospect many voters remain queasy about.

So what does it all mean? A classically earnest editorial would argue that Bush should be chastened by the Democrats’ gains, that he should heed his inner bipartisanship and reposition himself as the moderate candidate he was in 2000. But it’s too late for that. Bush is who he is, and any tactical adjustments he makes will be just that -- tactical adjustments.

That isn’t to say that he will “stay the course.� The need for both parties to cater to the revitalized center in the run-up to the 2008 presidential election will force change. No matter how defiant Vice President Dick Cheney and Defense Secretary Donald H. Rumsfeld want to be, Bush will be forced to find a face-saving, gradual exit from Iraq, not so much to placate Democrats but to placate his own potential GOP successors. Fixer James A. Baker III conveniently stands waiting in the wings with his bipartisan Iraq Study Group to provide cover for the orderly retreat.

The president will no doubt continue to press for the extension of his temporary tax cuts. Stay tuned for a tiresome and disingenuous semantic debate about whether failing to extend short-term relief amounts to a tax increase. At the risk of being classically earnest, we hope that the president, with an eye toward his legacy, will shift some fiscal policymaking away from his political advisors and empower Treasury Secretary Henry M. Paulson Jr. to propose and pursue some meaningful budgetary reforms. But we won’t hold our breath.

The Democrats have captured the House, but the most intriguing power shift in the aftermath of this election may not be from Republicans to Democrats but from Rove’s socially conservative base to more centrist GOP leaders. One of the ironies of Tuesday’s results is that it increases the leverage of moderate Republicans such as Sen. John McCain of Arizona, Sen. Chuck Hagel of Nebraska and former New York Mayor Rudolph W. Giuliani. Even as this election claimed so many of their kind, such moderates have the upper hand heading into 2008.