The same two senators have headed the Senate Environment and Public Works Committee for a decade, but depending on how the votes fall today, that could change. The panel, which oversees U.S. EPA and writes some of the federal government's most sweeping infrastructure bills, could get a new ranking Republican if Democrats retain control of the chamber. And if pre-election polling proves wrong and the GOP gains both the White House and the Senate tonight, the panel's leaders may stay the same, but their roles will change substantially to respond to new political realities.