The Democratic Party has regained control of both chambers of the United States Congress following significant victories in Tuesday’s midterm elections, ending the Republican Party’s dominance of the legislature.

Democrats secured a majority in the House of Representatives, where all 435 seats were contested, while also winning enough Republican-held Senate seats to take control of the 100-member upper chamber.

Among the major Senate victories was Democrat James Talarico’s defeat of Republican Ken Paxton in Texas, making him the first Democrat to win a Senate seat in the state since 1988.

In South Carolina, Democrat Annie Andrews defeated Republican Darline Graham, becoming the first woman elected to represent the state in the Senate and the first Democrat to win a Senate seat there in more than two decades.

Democrats also secured victories in North Carolina, where Roy Cooper defeated Republican Michael Whatley, and Ohio, where former Senator Sherrod Brown defeated Republican incumbent Jon Husted to reclaim his seat.

The victories reversed Republican control of the Senate, where the party had entered the elections with a 53–47 majority. Democrats needed a net gain of four seats to take control of the chamber.

The elections also saw Democrats retain key Senate seats, including Georgia, where incumbent Jon Ossoff defeated his Republican challenger, and New Hampshire, where Chris Pappas won the open seat.

The outcome represents a major shift in the balance of power in Washington, as Democratic control of Congress is expected to increase scrutiny of the Trump administration and create obstacles for its legislative agenda.

The midterm elections, held halfway through a presidential term, determine the composition of Congress and often serve as an indication of public sentiment towards the sitting administration.