As polls closed at 7 p.m. in six states, three of the most closely-watched Senate races remained as toss ups. CBS News estimates the Georgia, South Carolina and North Carolina Senate races are toss ups.
Democrats are fighting to take back control of the Senate, where Republicans hold a slim 53-47 seat majority. There are 23 Republican seats up for grabs in the Senate this year, as opposed to just 13 Democratic-held seats.
Democrats are also hoping to expand their majority in the House and add to their current 35-seat advantage.