Now, amid speculation over whom Gov. Brian Kemp might appoint to replace Isakson until a special election is held, some hopefuls are raising their hands for consideration. One of those prominent contenders is Rep. Doug Collins, who has emerged as one of President Donald Trump's chief defenders in Congress through his role as the top Republican on the House Judiciary panel.
But what exactly Kemp is looking for in a replacement is still largely unknown. The Republican governor — sidetracked by Hurricane Dorian barreling up the Eastern Seaboard — has said little publicly. That's despite being inundated by politicians and their supporters contacting him about the seat, according to an official familiar with the conversations who was not authorized to discuss deliberations and spoke on condition of anonymity.
Isakson said he plans to step down in December. Whomever Kemp appoints will serve for about 10 months before a special election on Nov. 3, 2020, for the remaining two years of Isakson's term. Georgia's other senator, Republican David Perdue, is also defending his seat on the November 2020 ballot. The two open Senate seats have raised Georgia's status as a must-watch 2020 battleground.
There will be no primary elections for Isakson's seat, meaning the special election will be open to qualified candidates from all political parties. That could significantly increase the likelihood of a runoff, required by Georgia law if no candidate receives over 50% of the vote.
Republican strategists say other potential candidates include U.S. Rep. Tom Graves and statewide officers like Lt. Gov. Geoff Duncan and Attorney General Chris Carr. When asked about Isakson's seat in a recent interview, Collins told The Associated Press: "If the governor were to ask me, would I like to take that position and begin that cycle? I would say yes."
Collins acknowledged that he has discussed the seat with Kemp, saying, "We had a short conversation that dealt with more than that." Collins has used his role on the Judiciary panel to criticize continued efforts by Democrats to investigate special counsel Robert Mueller's report on Russian election interference and obstruction of justice. While Collins has generally been well liked by lawmakers on both sides, he has become more confrontational since Democrats won the House majority and he ascended to the top GOP spot on the committee.
"This year, because of the majority's dislike of this president, the endless hearings into a closed investigation have caused us to accomplish nothing except talk about the problems our country is facing," Collins said in July as Mueller testified before the panel.
At the same time, he has worked with Democrats on legislation in the past. Collins, a former pastor, worked with New York Rep. Hakeem Jeffries on legislation to reform federal sentencing and prison laws that was eventually signed by Trump last year.
Brian Robinson, a Republican political adviser in Georgia who served as communications director under former Gov. Nathan Deal, says that several members of Georgia's congressional district have a "leg up" in seeking the appointment because they have the proven campaigning ability and fundraising network needed in such a short sprint.
Robinson said that Collins' relationship with the president could give him a big advantage. "Donald Trump likes Doug, and if Donald Trump weighs in for Doug, that's going to be very persuasive," Robinson said.
Associated Press writer Mary Clare Jalonick contributed to this report from Washington.