In Capitol Hill’s Rayburn office building, in the private chambers of the House Energy and Commerce Committee, hangs an enormous satellite photograph of the planet earth. Beneath the picture is a couch, where, according to sources familiar with the committee, long-time Chairman John Dingell is fond of sitting. From that couch, they say, the venerable Michigan Democrat, who has served for 53 years, has been known to point up to the photo and say, “That is the jurisdiction of this committee.”