When the Obama administration this past spring forced the bankrupt General Motors and Chrysler Corp. into virtual public receivership, officials justified the action as crucial to the survival of the auto industry and indeed the entire economy. Yet this unprecedented action has had several downsides, one of the less heralded of which has been the sudden vulnerability of current and retired employees who don't belong to a union. Case in point: the roughly 15,000 nonunion retirees of auto parts manufacturer and former GM subsidiary Delphi Corporation on the verge of losing their pension, health insurance and life insurance benefits.