Georgia Republican Sen. Johnny Isakson will retire at the end of 2019 due to his declining health, he announced Wednesday.

“In my 40 years in elected office, I have always put my constituents and my state of Georgia first,” the 74-year-old senator said in a statement. “With the mounting health challenges I am facing, I have concluded that I will not be able to do the job over the long term in the manner the citizens of Georgia deserve. It goes against every fiber of my being to leave in the middle of my Senate term, but I know it’s the right thing to do on behalf of my state.”

Isakson said that he has been increasingly feeling the effects from Parkinson’s Disease, and simultaneously dealing with a fall in July and surgery to remove a growth on his kidney. His resignation will be effective Dec. 31, he said. Under Georgia law, Gov. Brian Kemp, will appoint a replacement who will serve until the 2020 election, when the state will elect a permanent successor. Kemp said in a statement that he will appoint Isakson’s replacement “at the appropriate time.”

“No one embodies the heart and soul of Georgia more than Johnny Isakson,” Kemp said.

Isakson’s resignation means that two Senate seats in Georgia are up for grabs in 2020, giving the Democrats another opportunity in their long-shot bid to retake the Senate. Immediately after the news broke, speculation began percolating about who Democratic party leadership would be able to recruit, with many pundits pondering whether this vacancy could convince Stacey Abrams to jump into the ring. Abrams challenged Kemp in the 2018 gubernatorial election, narrowly losing. She declined to run for Senate in order to focus on voting rights efforts in 2020.

Abrams however, quickly quashed the rumors. “Leader Abrams’ focus will not change: she will lead voter protection efforts in key states across the country and make sure Democrats in Georgia are successful in 2020,” her spokesman said in a statement.

Isakson, who has served in the Senate since 2005 and chairs both the Veterans’ Affairs and the Select Committee on Ethics in the Senate, is respected on both sides of the aisle, and sentiments from his colleagues immediately began pouring in. “No one is more respected by the other members of the Senate than Johnny Isakson is,” said Missouri Sen. Roy Blunt, citing their two decades of friendship. “I will miss his leadership and his advice when he leaves the Senate, but look forward to his continued friendship.”

“Folks on both sides of the aisle are going to miss [Senator Isakson],” Democratic Sen. Mark Warner wrote on Twitter. “He’s a gentleman who’s spent his career looking for common ground and actually trying to accomplish something in Washington.”

The news of Isakson’s resignation was preceded by a wave of retirement announcements from Republicans in the lower chamber. Earlier this week, Rep. Sean Duffy, who was elected to Congress in the Tea Party wave of 2010, said he was retiring next month to deal with a family situation. In total, at least ten members announced in August alone that they planned to retire.

Write to Alana Abramson at Alana.Abramson@time.com.