Republican Ron Johnson has defeated Democratic candidate Mandela Barnes in the Wisconsin Senate election, according to a projection from DecisionDeskHQ.

Decision Desk made the projection at 2:23 a.m. EST on Wednesday.

Polls for the race, which was one of the most closely watched midterm races, flipped in the months leading up to the election with Barnes leading in many polls early in the summer, but Johnson jumping into the lead during the fall. 

The Wisconsin race was seen as critical for both parties, with it being a must-hold seat for Republicans to have a chance to gain control of the chamber, which is deadlocked at 50-50. Democrats saw the seat as a possibility to build on the technical majority they held with Vice President Kamala Harris casting tie-breaking votes.