Energy Mandates Fuel a Rift Bush's Proposal Pits Coal Interests Against Environmentalists By JOHN J. FIALKA January 26, 2007 WASHINGTON -- Raising the federal mandate for using renewable and alternative energy sources may mean bigger government incentives for efforts to turn coal into diesel-engine fuel. But President Bush's push for domestic alternatives to imported oil has ignited a battle between coal interests and environmentalists -- and underscored tension between the goals of increasing U.S. energy security and curbing global warming. Greater use of liquid fuels made from coal, the nation's most plentiful energy source, would reduce reliance on imported oil....