The Mexican vein of populism is more a technique of gaining domestic political support and shoring up the leadership than it is an ideology for export. The main reason for this is, among other idyosincracies, Mexico's cunning "isolationism" in foreign policy, which works better the more politically correct it is.

Should he make it to the presidency, Lopez Obrador is more likely to tread the same path as past PRI presidents: non-interventionism and self-determination as speechwriter's tenets, along with selfish, quiet regional diplomacy run by professionals. Given that, Washington should avoid equating Lopez Obrador with Hugo Chavez.

In a brilliant article on the subject, Jorge Castaneda recently wrote, "Instead of arguing over whether to welcome or bemoan the advent of the left in Latin America, it would be wiser to separate the sensible from the irresponsible and to support the former and contain the latter." Winning an election in Mexico, even in the post-PRI era, takes a lot of daring -- a daring that might lead a man like Lopez Obrador to sound too irresponsible and too left-leaning to any Washington observer. Certainly, there is something about Mr. López Obrador that reminds one of Robert Penn Warren's Willie Stark. But I have a hunch that he decided a long time ago to put the sensible man in him to work once he's in office, but not till then.