Pipes for Transcanada Corp.'s planned Keystone XL oil pipeline are stacked at a depot in Gascoyne, N.D. The House of Representatives approved the Keystone XL pipeline Friday; the Senate voted against it on Tuesday. Andrew Cullen/Reuters/Landov hide caption

itoggle caption Andrew Cullen/Reuters/Landov

Sen. Mary Landrieu, D-La., chair of the Senate energy committee, spoke Wednesday about getting congressional approval for the Canada-to-Texas Keystone XL pipeline. With her is Sen. Joe Manchin, D-W.Va., a member of the committee. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Rep. Bill Cassidy, R-La. (right), poses with his family and House Speaker John Boehner at the start of the new Congress, on Jan. 3. On Wednesday, Cassidy announced that he would challenge Democratic Sen. Mary Landrieu in 2014. Cliff Owen/AP hide caption

itoggle caption Cliff Owen/AP