The big political news this morning--announced, appropriately, via an exclusive interview with Paul Gigot on the Wall Street Journal editorial page--is that Karl Rove is leaving the White House at the end of this month.

There's already some speculation that Rove is leaving to get out of the spotlight of congressional (and perhaps criminal justice system) scrutiny of the Bush administration's many crimes and misdemeanors--or, to follow a very different theory, to join the presidential campaign of Fred Thompson, due to announce next month. We'll know soon enough about that proposition. But it's as good a time as any to assess the legacy of this strange, frightening, and ultimately defeated man.

Tne first place to stop in understanding Rove's legacy is the masterful profile of Rove published in The New Yorker by Nicholas Lemann in August of 2003 (indeed, the title of today's Gigot piece, "The Mark of Rove," alludes to a term used by Lemann to denote acts of political skullduggery not directly attributable to Rove, but bearing his "mark").

Lemann's main thesis is that Rove's M.O. was perfected in a series of campaigns in Texas (and I could add, in Alabama) in the late 1980s and early 1990s, which led to a Republican takeover of the state, top to bottom. From a strategic point of view, the "marks of Rove" were: (1) an abiding belief in ideological polarization, particularly on highly emotional issues, as the One True Way to win elections, not only by solidifying the conservative base but by forcing swing voters to pick sides on favorable terms; (2) a direct-mail specialist's attention to electoral segmentation and what is now known as "micro-targeting;" (3) an insistence on the use of policy initiatives to attract, reward or punish specific constituencies; (4) an intense focus on the nexus between politics, policy and partisan funding sources; (5) a complete lack of inhibition about nasty, negative political tactics; and (6) a taste for secrecy and indirection.

It's hard to identify any political or policy triumph or defeat during the Bush administration that is not essentially attributable to one of Rove's characteristic traits. It's true that Rove probably had little to do directly with the failed occupation of Iraq or the abandonment of New Orleans after Katrina. But on the other hand, rewarding Republican campaign contributors and activists with fat contracts and jobs in Iraq certainly bore some "mark of Rove," as did the administration's favoritism towards Republican-governed Mississippi and Alabama after Katrina.

In the end, all Rove's designs ultimately backfired. Rovian polarization ultimately united the Democratic Party in intense opposition to Bush. Failed politically-driven policies, and the corruption borne of constituency- and funder-tending by the White House and Congress, ultimately drove independents into the arms of Democrats, And one of Rove's prize swing-voter initiatives, immigration reform, blew up spectacularly, alienating the GOP's conservative base and Latino voters as well.

It is sometimes forgotten that the peak era of Rove's influence, the re-election of George W. Bush in 2004, produced a no-margin-for-error win and narrow Republican majorities in Congress, despite the unexpected windfall to Rovian politics provided by 9/11. It's seemed like a long way down for Bush and the GOP since then, but in truth, Bush's popularity was never high except in a few crucial moments.

As an American citizen, I am personally happy that this man will soon no longer be on the public payroll. But for political analysts, it will be important to deconstruct the various theories of the "boy genius," which seemed so darkly brilliant not that long ago, to identify the fatal arrogance and folly that was there all along.