Sen. Lamar Alexander, a Republican from Tennessee who is currently in the middle of his third Senate term, announced on Monday that he would not seek reelection in 2020.
"I will not be a candidate for re-election to the United States Senate in 2020. The people of Tennessee have been very generous, electing me to serve more combined years as Governor and Senator than anyone else from our state," Alexander said in a statement. He added that "I am deeply grateful, but now it is time for someone else to have that privilege."
Alexander has a long career as an establishment Republican. After serving as governor of Tennessee for two terms from 1979 to 1987, he became Secretary of Education under President George H. W. Bush from 1991 to 1993. In 2002, a year when Republicans benefited from post-9/11 sentiments to overperform despite holding the White House (a status quo that usually works against the incumbent party), Alexander was elected to his first Senate term. He was reelected in 2008, even though that was a Democratic year, and again during the GOP-favorable climate in the 2014 midterm elections.
It is unclear which Republican could replace Alexander in Tennessee. Although the outgoing Gov. Bill Haslam declined to seek the seat being vacated by Republican Sen. Bob Corker earlier this year, he may change his perspective now that his own gubernatorial term is ending. If Haslam did decide to seek the office, he would immediately be considered one of the frontrunners and could have a decisive edge over his potential competitors.
CNN elaborated on some of the other prospective replacements for Alexander:
The state's GOP members of Congress will also be closely watched. A Donald Trump-style candidate, potentially like Rep.-elect Mark Green, could emerge. The Tennessee Republican, speaking on the condition of anonymity to discuss the potential field frankly, also pointed to Rep. Chuck Fleischmann, former Rep. Stephen Fincher (who lost the 2018 Senate primary to Sen.-elect Marsha Blackburn), US Ambassador to Japan Bill Hagerty and orthopedic surgeon Manny Sethi, who co-edited a health policy book with former Sen. Bill Frist.
Alexander's announcement comes shortly after he prominently criticized a recent decision by a Texas court to repeal the Affordable Care Act. Although Alexander is an opponent of the law, he explained in a statement that "if the U.S. Supreme Court eventually were to agree that Obamacare is unconstitutional — which seems unlikely, however poorly the law was written — I am confident that any new federal law replacing it will continue to protect Americans with pre-existing conditions who buy health insurance."