Yesterday’s special election to replace the disgraced Randy “Duke” Cunningham will go to a June runoff between Democrat Francine Busby and former GOP congressman Brian Bilbray. The demographics of the district suggest that Bilbray should win, but Busby clearly benefits from the Cunningham scandal and general disgruntlement with Republicans. Lots of election-watchers will regard the runoff as a bellwether for November, especially if Busby wins.