Democrats will stay in control of the U.S. Senate next year after Democratic Senator Catherine Cortez Masto won re-election in Nevada, handing a major victory to U.S. President Joe Biden.

Still, Republicans remained close to winning control of the U.S. House of Representatives as officials continued counting ballots cast in Tuesday’s U.S. midterm elections.

Cortez Masto narrowly defeated Republican challenger Adam Laxalt, a former state attorney general who was endorsed by former President Donald Trump.

With Masto’s victory on the heels of Democratic Senator Mark Kelly winning re-election in Arizona late on Friday, Democrats will control at least 50 Senate seats, with Vice President Kamala Harris able to break ties in the 100-member chamber.

The Senate is split 50-50 between Democrats and Republicans. The newly elected Senate will be sworn in on January. 3.