In this April 22, 2008 file photo, House Energy and Commerce Committee Chairman Rep. John Dingell, D-Mich. presides over a hearing of the committee on Capitol Hill in Washington. Rep. Henry Waxman of California has been selected by a key Democratic leadership panel to replace Dingell to head the crucial House committee with jurisdiction over energy, global warming and many other issues like health care. Waxman and Dingell, D-Mich. , will still square off Thursday in a vote of House rank and file Democrats. AP Photo logo AP Photo 19 months ago

In this April 22, 2008 file photo, House Energy and Commerce Committee Chairman Rep. John Dingell, D-Mich. presides over a hearing of the committee on Capitol Hill in Washington. Rep. Henry Waxman of California has been selected by a key Democratic leadership panel to replace Dingell to head the crucial House committee with jurisdiction over energy, global warming and many other issues like health care. Waxman and Dingell, D-Mich. , will still square off Thursday in a vote of House rank and file Democrats.