When an ambitious state attorney resigns his post as the top prosecutor in Palm Beach County to become a lawyer for a fossil fuel company, eyebrows will inevitably rise. But it was an especially strange move for Michael McAuliffe, because the Democratic litigator left to work for Bill Koch, one of Mitt Romney's top fundraisers and brother of the famed Tea Party backers Charles and David Koch. What could Palm Beach billionaire Koch want from McAuliffe? Koch is known to be litigious, having waged famous court battles against a wine broker and a former mistress. In the '80s, he sued his brothers, alleging corporate mismanagement of the family's oil company, Koch Industries. Last year, Bill Koch's company, Oxbow Corp., sued Warren Buffett's railroad companies, alleging that Union Pacific and Burlington Northern Santa Fe Railroad companies were conspiring to drive up costs for shipping coal. None of this explains why McAuliffe decided to join his legal team. It's the kind of political mystery that will keep tongues wagging for months.