Republicans have now picked up a third Senate seat. This one is in South Dakota.

BREAKING: GOP Mike Rounds wins election to U.S. Senate in South Dakota. @AP race call at 9 p.m. EST poll close. #Election2014 #APracecall

— The Associated Press (@AP)
November 5, 2014

The other two pick-ups (so far!) are West Virginia and Arkansas. Republicans must pick-up six seats in the Senate to gain control of the upper body.