WASHINGTON — It was after midnight and every lawmaker in the committee room wanted to go home, but there was still time to sweeten a deal encouraging oil and gas companies to drill in the Gulf of Mexico. ‘There is no cost,’ declared Representative Joe L. Barton, a Texas Republican who was presiding over Congressional negotiations on the sprawling energy bill last July. An obscure provision on new drilling incentives was ‘so noncontroversial,’ he added, that senior House and Senate negotiators had not even discussed it. Mr. Barton’s claim had a long history. For more than a decade, lawmakers and administration officials, both Republicans and Democrats, have promised there would be no cost to taxpayers for a program allowing companies to avoid paying the government royalties on oil and gas produced in publicly owned waters in the Gulf. But last month, the Bush administration confirmed that it expected the government to waive about $7 billion in royalties over the next five years, even though the industry incentive was expressly conceived of for times when energy prices were low. And that number could quadruple to more than $28 billion if a lawsuit filed last week challenging one of […]