Colorado

Senator Wayne Allard said he would limit himself to two terms, and he is not going back on his word. The opening sets up a race between Democratic Congressman Mark Udall and former Congressman Bob Schaffer in a state that is increasingly purple: Colorado did re-elect Bush in 2004, but with just 52% of the vote, and at the same time it chose to send Democrat Ken Salazar to the Senate with 51% of the vote. And Allard never has an easy race, winning reelection in 2002 with just 51 % of the vote. The GOP had hoped that former Governor Bill Owens — who has a proven statewide track record and name recognition — might run, but when he declined they settled on Schaffer. As of June 30 Udall, the son of the legendary Colorado Congressman Mo Udall and a former executive director of the Colorado Outward Bound Program, had more than 3.5 times more money on hand: $2.5 million to Schaffer's $683,000. "Mark Udall is the favorite," Cook said. "I'd be surprised if the Democrats didn't win this one."

— Jay Newton-Small/Washington