Behind House Struggle, Long and Tangled Roots With Representatives Henry A. Waxman and John D. Dingell locked in a fearsome struggle for the chairmanship of the powerful House Energy and Commerce Committee, Steny H. Hoyer, the No. 2 Democrat in the House, was trying to broker a truce. Two days after Mr. Waxman announced his challenge this month, Mr. Hoyer asked if he would be willing to wait two years, to allow Mr. Dingell, the longest-serving House Democrat, a graceful exit and to preserve the Congressional seniority system. Mr. Waxman said no. Mr. Hoyer, of Maryland, then asked Mr. Dingell, of Michigan, if he would accept the deal: two years and out. Emphatically, no, Mr. Dingell said. If Mr. Waxman, of California, the darling of environmentalists and the liberal wing of the party, wanted the Energy and Commerce crown, he was going to have to take it by parliamentary force. And that is precisely what he did on Thursday morning, by a vote of 137 to 122, with the decisive votes coming from the large California delegation and the newest members of the Democratic Caucus. The roots of the Dingell-Waxman clash go back years, even decades, and have both personal and substantive causes....