Iowa Sen. Chuck Grassley, 87, tests positive for COVID-19

FILE - Senator Chuck Grassley (R-IA) makes a statement after voting in the Judiciary Committee to move the nomination of Judge Amy Coney Barrett to the Supreme Court out of committee and on to the Senate for a full vote on October 22, 2020 in Washing (Photo by Samuel Corum/Getty Images)

Iowa Sen. Chuck Grassley, the longest-serving Republican senator and third in the line of presidential succession, said Tuesday that he has tested positive for the coronavirus.

Grassley announced earlier Tuesday that he was quarantining after being exposed to the virus and was waiting for the results of a test. On Tuesday evening, he tweeted that he had tested positive.

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“I’ve tested positive for coronavirus,” Grassley wrote. “I'll b following my doctors’ orders/CDC guidelines & continue to quarantine. I’m feeling good + will keep up on my work for the ppl of Iowa from home.”

Grassley said he looks forward to “resuming my normal schedule soon.”

The Iowa Republican, who was in the Senate and voting on Monday, did not say how he was exposed. His office said Tuesday morning that he was not experiencing any symptoms.

Grassley is the president pro tempore of the Senate, meaning he presides over the Senate in the absence of Vice President Mike Pence and is third in line to become president, behind Pence and House Speaker Nancy Pelosi. The president pro tempore is the senator in the majority party who has served the longest.

By missing votes Tuesday, Grassley broke a 27-year streak of not missing a single Senate vote. According to his office, the last time he missed a vote was in 1993, when he was in Iowa assisting with relief efforts after severe flooding.

Grassley was first elected to the U.S. House in 1974 and then to the Senate in 1980. He is the chairman of the Senate Finance Committee and is expected to become the top Republican on the Senate Judiciary Committee when a new Senate session begins in January.