The Associated Press has declared incumbent US Senator Dick Durbin the winner in his re-election bid.
Durbin faced republican State Senator Jim Oberweis in the election. Democratic incumbents also won in Delaware, Michigan, and Rhode Island.
Republicans are halfway there in their fight to win control of the US Senate. Republican Mike Rounds won a Democratic-held Senate seat in South Dakota, the third of six the GOP needs for a Senate majority.
The onetime South Dakota governor won a four-way race to replace Democratic Sen. Tim Johnson, who is retiring.
