Bruce Yandle's great expression refers to the unholy coalition that supports "perverse" regulation on things like sex, drugs and water utilities. (Read his version here.)
By unholy, I mean that a group of people opposed to an activity informally align with a group of people who support that activity but who gain if that activity is restricted. Both Baptists and bootleggers want to restrict the sale of alcohol on Sunday -- for different reasons: Baptists think consuming alcohol on Sunday is a sin; bootleggers do not want competition from stores. A law restricting the sale of alcohol on Sunday therefore results in higher profits for bootleggers, and breaking the law for drinkers. It's debatable whether or not overall sin declines.
Numerous examples of B&B coalitions exist: drug warriors & drug dealers, prudes & pimps, and bureaucrats & water executives.
What's your favorite combination?