LIVE: US Senate election results

With 34 seats up for election Tuesday night, the balance of power in the United States Senate is up for grabs.

Democrats currently have the majority in the Senate.

Democrats hold 47 of the chamber's 100 seats. Republicans have 49 seats. Along with those 47 Democrats, four independent senators usually vote with the Democrats, giving them a voting majority.

All four independent seats are on their respective state's ballot this year with Sen. Kyrsten Sinema (I - Ariz.) and Sen. Joe Manchin (I - W. Va.) not running for reelection. The other independent senators are Bernie Sanders (I - Vt.) and Angus King (I - Maine).

How does the Senate work?

The United States Senate consists of two members from each state for a total of 100 members.

Each Senator serves a six-year term.

The vice president serves as president of the Senate. The vice president serves as the presiding officer and has the sole power to break a tie in the Senate and presides over the receiving and counting of electoral ballots in presidential elections.

The chamber must also appoint a President Pro Tempore to serve as the presiding officer in the absence of the vice president.

The position is currently held by Sen. Patty Murray (D-Wash.).