Working the halls of Congress, lawmaker by lawmaker, to end the ban on U.S. crude oil exports, oil-state senators and energy company executives were united by a single strategy and bolstered by seismic shifts in the industry. “We can’t let this issue get Keystone-d,” said Senator Heidi Heitkamp, a North Dakota Democrat, referring to the years-long, ultimately futile battle to have an oil pipeline from Canada to the Gulf of Mexico approved over the objections of environmentalists. To avoid meeting a similar fate in their efforts to overturn the 40-year-old U.S. policy, the cadre fanned out across the Capitol, arguing in meetings that lifting the ban was about jobs and the economy — not the environment, or the future of fossil fuels. Exports would boost the nation’s economy and help put Americans to work, they said. The backbone of their argument, unthinkable a decade ago, was that the U.S. […]