Democratic chances of holding the Senate improve. Dramatically.

Ohio Sen. Sherrod Brown's strength has put a damper on GOP efforts to win control of the Senate this November. The early conventional wisdom was that Democrats would have a tall order holding the Senate in 2012. Not only did they have few pickoff opportunities of their own, but they were playing defense in some seriously tough territory.

These days, however, the Senate is looking much safer. Follow me below the fold for a complete rundown.