The news that Senator Johnny Isakson will resign from his Senate seat by the end of the year for health reasons makes the prospect of the GOP holding onto its narrow three-seat majority scarier. Richard Baehr writes:

Isakson was the slight favorite to hold his seat. Georgia's white percentage is now about 60 percent, and black turnout is soaring (about a third, voting 95% Dem). This is now a tossup race, and the GOP's hold will depend on the candidates picked by both parties, and how Trump does in the state. It is no sure thing he will win it in 2020 (he won by 5% in 2016), and the governor's race was a 1% race in 2018.

Isakson's seat was through 2022, but now the Republican governor will appoint a fill-in, through end of 2020. So whoever is appointed or whoever turns out to be GOP nominee, if there is a primary, will have to run in 2020, and then again in 2022.

David Perdue's GOP-held Senate seat is up in 2020, and this is the one the Dems hoped Stacey Abrams would run for. So in 2020 there will be two Georgia Republicans defending Senate seats. There will be added pressure now on Abrams to run for one of the two seats. If she runs, that will enhance black turnout, threatening Trump's ability to win the state.

The GOP has 53 senators. They should win Alabama to get to 54. Colorado and Arizona are two good pickup chances for the Dems. Now you have two Georgia seats plus North Carolina and Maine at risk.

It is not at all hard to imagine Dems controlling both houses of Congress and the White House.

In Politico, James Arkin examines the potential candidates for the Senate in Georgia:

It's unclear who will ultimately be in the race on either side. Several Republicans are considered candidates for the appointment after Isakson departs at the end of the year: Lt. Gov. Geoff Duncan; state Attorney General Chris Carr; and Reps. Doug Collins and Tom Graves. On the Democratic side, operatives listed several potential contenders, including Michelle Nunn, who lost to Perdue in 2014; Jason Carter, who lost the race for governor that year; and Rep. Lucy McBath, who flipped a suburban House district last year. Asked Wednesday if he would consider running for Senate, Carter, the grandson of former President Jimmy Carter, said, "I think anybody would think about it." Three candidates are already running for Senate against Perdue: former Columbus Mayor Teresa Tomlinson, Clarkston Mayor Ted Terry and businesswoman Sarah Riggs Amico, who lost the race for lieutenant governor last year and announced her campaign earlier this week. All three confirmed they plan on staying in the race against Perdue. One other potential candidate is Jon Ossoff, who lost an expensive and closely watched special election for Congress in the Atlanta suburbs in 2017. Ossof [sic] is leaning towards running, according to a person who has spoken with him and was granted anonymity to share private conversations. This week's developments did not change his timeline but did open up the question of which seat he would run for. Ossoff has already spoken with potential campaign managers and has had discussions with veteran pollster Fred Yang about working for his potential campaign, according to multiple Democrats familiar with the conversations. Yang did not return an email requesting comment.

Stacey Abrams caricature by Donkey Hotey.