Just four years after he slid out of the White House as the embattled Rasputin to a flailing president, Karl Rove has reinvented himself as the dominant private citizen in the Republican Party. He is today a driving force behind both the powerful advocacy organization Crossroads GPS and its even more influential sibling, American Crossroads, the largest SuperPAC on the right. Meanwhile, even as he has been raising money to defeat Democrats, the 60-year-old Rove has carved out a second career as a well-paid pundit for Fox News and as a columnist for The Wall Street Journal—and, in that role, he has been at times merciless in policing his own side of the political spectrum. As the Republican campaign has unfolded, Rove the pundit has frequently seemed offended by the self-destructiveness of every GOP contender not named “Mitt Romney.” From the outset, Rove belittled longtime foe Rick Perry for reinforcing his dumb “cowboy from Texas” image. He was scathing over Michele Bachmann’s false claims that the HPV vaccine causes mental retardation. And, after Herman Cain catastrophically botched a question about Libya, Rove dubbed him “not ready for prime time.”

The upshot of all this activity is that, for the second time in recent years, political junkies of both the right and the left are obsessed with Rove’s nefarious influence. Based on his Fox News critiques, some Tea Partiers, including Cain, believe that he is secretly in the Romney camp, even though Rove has never been close to the former Massachusetts governor. Democrats, in turn, seize on every TV commercial that American Crossroads puts on the air as evidence that Rove still practices guttersnipe politics. A mid-November press release from the Democratic Senatorial Campaign Committee (DSCC) was headlined: “KARL ROVE'S RIGHT WING FRONT GROUP PROPS UP SENATE REPUBLICANS WITH ATTACK ADS.” These days, Rove vies with Rush Limbaugh as the leading target of liberal demonology.

There is no doub...