U.S. Sen. Bob Corker, R-Tenn., joined a group of senators Thursday in a letter asking Senate Majority Leader Harry Reid and Senate Republican Leader Mitch McConnell to allow the Oct. 1, 2008, expiration of current bans on American energy exploration and production. The letter was authored by U.S. Sen. Jim DeMint, R-S.C. In addition to DeMint and Corker, the letter is signed by Sen. Lamar Alexander, R-Tenn., and 36 other Republican senators. "We need a balanced approach that will allow us to produce more energy here at home and use less, with a strong emphasis on conservation as we move...