Legislation approving the Keystone XL pipeline , which lawmakers will take up as soon as this week , will open the first broad debate on energy policy in Congress in eight years and give the new Republican majority a chance to push for significant changes to President Barack Obama ’s agenda. GOP lawmakers, who now control the Senate and have a firmer hold on the House, are planning measures that would aim to spur greater development of fossil fuels and curtail a series of Mr. Obama’s environmental regulations, including ones cutting greenhouse gas emissions. Republicans are […]