Republican wins in Ohio and West Virginia put the party two seats ahead in the race for control of the U.S. Senate.
Republican businessman Bernie Moreno beat incumbent Sen. Sherrod Brown, D-Ohio, improving Republican chances of taking back control of the Senate.
Moreno came out on top in the most expensive Senate race in the nation, which saw $536 million spent.
Republican Jim Justice won the West Virginia Senate race, giving the party its first gain of the night.
Justice won the seat held by retiring Independent Sen. Joe Manchin, who was a Democrat until he left the party earlier this year.
Pollsters expected Justice to beat Democratic challenger Glenn Elliott.
Thirty-three seats are up for grabs in the Senate, including 19 held by Democrats and 10 by Republicans.
The remaining four seats are held by Democratic independents, namely Sens. Kyrsten Sinema, Bernie Sanders, Angus King, and Manchin.
Fifty-one seats are needed for control of the Senate.
