Normally when an incumbent senator announces he or she won’t be seeking reelection, it is a liability for that senator’s party. That’s especially true when the senator represents a swing state that just reelected a senator from the other party and went for the other party’s presidential candidate in the last election. But Sen. John Ensign’s (R-NV) is like former Sen. Chris Dodd’s (D-CT): it’s a rare retirement that actually increases his party’s chances of keeping his Senate seat.
