Republican Sen. Gordon Smith of Oregon is touting his work with Barack Obama to improve automobile fuel efficiency and his "bipartisan leadership for energy independence" in a new television ad. Smith, the sole GOP senator on the West Coast, is fighting to maintain his seat this year in what's expected to be a tightly contested race against Democratic challenger Jeff Merkley. Watch it:

The Obama campaign issued a statement yesterday on their candidate's appearance in the ad. "Barack Obama has a long record of bipartisan accomplishment and we appreciate that it is respected by his Democratic and Republican colleagues in the Senate. But in this race, Oregonians should know that Barack Obama supports Jeff Merkley for Senate. Merkley will help Obama bring about the fundamental change we need in Washington," said Obama campaign spokesman Bill Burton.

Smith is seen as one of the most vulnerable GOP incumbents in the Senate this year in part because of his environmental record. He maintains only a 32 percent lifetime score [PDF] from the League of Conservation Voters. However, he upped his term score significantly in 2007, earning a 73 percent in the first term of the 110th Congress.