Who Controls the Senate in a 50-50 Tie? 

Article I, Section 3 of the Constitution specifies that The Vice President is the President of the Senate. The Vice President has no vote unless to break a tie in some matter before the Senate.

Therefore, if there is a 50-50 party split in the Senate, the Vice President's vote will give the majority to his or her party. That occurred most recently in the 117th Congress (2021-22), where Vice President Kamala Harris was the tiebreaking vote.

In the 2024 election, 34 Senate seats will be contested. Heading into that election, Democrats hold a 51-49 partisan advantage. Republicans can retake control in January, 2025 with a net gain of two seats or by winning the 2024 presidential election along with a net gain of one seat.