President Obama's announcement that BP would set aside $20 billion in a fund for victims of the Gulf spill is a welcome relief to communities where businesses and homes have been destroyed. The total amount needed to compensate, however, is being estimated at closer to $60 billion. Obama swears the 20 is not a cap -- I guess we'll see. More to the point: Since the president had no legal basis to demand the set aside, on what basis did he extract those billions?