Republican Jim Justice is expected to win an open Senate seat in West Virginia as soon as the polls close, taking over the seat previously held by Joe Manchin, a Democrat turned independent.

In Ohio, many US media outlets predict that Republican candidate Bernie Moreno will defeat incumbent Democrat Sherrod Brown.

Photo: Screenshot of The Hill

Those two wins ensure that Republicans will hold at least 51 seats, enough to take control of the Senate, with the potential for further gains as results from other competitive races come in, according to Reuters.

Fox News also predicted Republicans would win at least 51 seats in the Senate, while Democrats would win 43 seats.

Republicans also recorded gains as they sought to retain control of the House of Representatives, where they hold a narrow 220-212 majority, according to Reuters.

They won three seats from Democrats in North Carolina, while Democrats took control of a Republican-held seat in Alabama.

According to Fox News, Republicans won 178 seats in the House of Representatives, while Democrats won 147, while each party needs to win at least 218 seats to take control. Meanwhile, according to ABC News, Republicans won 199 seats, while Democrats won 186 seats.

Democrats now need to flip at least six seats to take control of the 435-seat House of Representatives, according to Reuters.

The outcome remains uncertain in the House of Representatives, although Republicans won North Carolina. Analysts say Democrats could easily win enough seats to take control of the House.

Tight races in the heavily Democratic states of New York and California could decide control of the House, although the final results may not be known for several days because California typically takes several days to count votes.

Meanwhile, voters made history in Delaware, where they elected Democrat Sarah McBride as the first openly transgender member of the US Congress, according to Reuters.