Sen. Ron Johnson (R-WI) has tested positive for the coronavirus, his office said Saturday. “Senator Johnson feels healthy and is not experiencing symptoms. He will remain isolated until given the all-clear by his doctor,” the spokesperson said. He is the third Senate Republican to announce a positive test result in the last 24 hours, after Sen. Thom Tillis (R-NC) and Sen. Mike Lee (R-UT). Their diagnoses potentially jeopardize the Senate’s efforts to push forward Judge Amy Coney Barrett’s Supreme Court confirmation before the election.

Johnson had only just finished two weeks of quarantine on Tuesday after being exposed to someone with coronavirus on Sept. 14. He was supposed to travel with President Trump on Sept. 17 but canned it after learning he had to quarantine. He tested negative at the time, his spokesperson said. But, when he returned to D.C. on Tuesday, he was again exposed to someone who later tested positive. He took a test on Friday that came back positive.