ATLANTA (Reuters) — Nearly 2.1 million people have cast ballots in a U.S. Senate runoff election in Georgia that will determine whether Democrats control both chambers of Congress and the fate of President-elect Joe Biden’s agenda, according to state data published Thursday.

More than a quarter of the state’s registered voters have either cast ballots early or through the mail, the state’s figures show, a sign that turnout in the pair of Senate races will be high. About 4 million Georgians voted early in the November election, in which Democrat Biden defeated President Donald Trump.

The runoffs pit Democratic challengers Raphael Warnock and Jon Ossoff against Republican incumbents Kelly Loeffler and David Perdue, respectively. The runoff election was necessary because no candidate won more than 50% of the vote on Nov. 3.

The state releases information about the number of people who voted, but does not tally their votes until election day.

About 1.3 million people voted early at in-person polling places, according to the state data. Another 721,000 sent ballots by mail. A total of about 1.3 million Georgians requested mail-in ballots.
The outcome of the race will be critical in shaping Biden’s agenda after he takes office.

If Republicans win one or both Senate seats in Georgia, they will retain a slim majority in the chamber and can block Biden’s legislative goals and judicial nominees. If Democrats win both, the chamber will be split 50-50, giving the tiebreaking vote to Vice President-elect Kamala Harris.

Voting in the Senate runoffs ends on Jan. 5.    

Turnout has been higher in some of the heavily populated areas around Atlanta that delivered Biden a narrow victory in the state. About 30% of registered voters in Fulton County, which includes Atlanta, had voted by Thursday, as had about 32% of voters in suburban DeKalb County.