It's not just "Bush's Brain" that's leaving the White House, but a whole generation of Republican theorizing that is being shunted aside. As Karl Rove exits, a newer conservative movement will enter — which, come to think of it, is actually the older conservative movement that Rove & Co. sought to bury.

I first met Karl Rove in 1982, when I was a young White House staffer. Having known most top political operatives, at least on the Republican side, over the past 30 years, I can fairly state that Rove is as savvy as any of them when it comes to campaigns and elections.

His success with George W. Bush — guiding him from the private sector to the Texas governorship to the White House in just six years — would be enough alone to assure Rove's place in the history books.

But Rove, of course, wanted to be more than just a political consultant. He wanted to be taken seriously as a policy intellectual, which is why he went into the White House in 2001, eschewing the fortune he could have made as a well-wired wheeler-dealer if he had stayed "outside." Rove's policy vision was deeply influenced by what might be called the "libertarian-universalist" school of thought within the Republican Party; that's what he brought with him to meetings in the West Wing.

One leading exponent of this libertarian-universalism was former New York Rep. Jack Kemp. Three decades ago, Kemp embraced "supply side" economics, which he then sold to the rest of the Republican Party. Tax rates were counterproductively high in the '70s, and so cutting them was a good idea. Indeed, the economy soared in the '80s and has been mostly soaring ever since; even many Democrats now see the wisdom of low tax rates.

But Kemp's vision went further than cutting taxes. A whole generation of Republicans, including Rove, came to see most political issues as ultimately economic issues. The goal was to make sure that everyone — at least everyone on their side of the aisle — got a bigger piece of the pie. And as long as the economy was growing, tax cuts could be coupled with spending increases. Thus "big government conservatism" was born.

As time went by, this libertarian-universalist vision grew ever more expansive. If everyone is driven by money, the thinking went, why not let everyone come to America? Why worry about border control? Why worry about something as quaint as American identity, when what really matters is the miracle of the market? More immigrants equals more economic growth and a higher stock market, which means we can privatize Social Security and make everyone a rich investor, whether he or she speaks English. That was the domestic policy vision of the White House and, seemingly, the foreign policy vision, too.

But as Bush and Rove cruised toward the far shore of Republican realignment, they didn't notice big icebergs in the water. First, most Americans were not keen on value-free, market-driven multiculturalism. To the generally conservative majority, America wasn't a "theory"; it was a home that needed safeguarding. That's the older conservatism that Rove sought to supplant. And meanwhile, signature Rove domestic policies — "personal accounts" for Social Security and "comprehensive immigration reform" — both sank.

The second iceberg was 9/11 and the clash of civilizations that it heralded. Bush and Rove benefited from the "rally 'round the flag" effect in the 2002 and 2004 elections, but neither man understood that 9/11 signaled the rejection of libertarian-universalism, not the chance to spread its benefits to the Middle East. People kill and die for their land and for their faith, crazy as that might seem to economists. That's the iceberg of stubborn reality that sank Bush.

But as noted, Rove the pol isn't dumb, even if he did overreach, policywise. So he'll survive to do more campaigns, even as his old boss sinks from view.

James P. Pinkerton is a columnist for Newsday. Reach him at pinkerton@ix.netcom.com.