U.S. Senator Lamar Alexander won't see re-election in 2020.
The 78-year-old veteran senator made the announcement Monday.
The Maryville native served two terms as Governor of Tennessee.
He was also the president of UT, and was US Secretary of Education under President George H.W. Bush.
Alexander was first elected to the U.S. Senate in 2002.
"I decided that it was time for somebody else to have the privilege," Alexander said.
The Maryville native has been part of Tennessee politics for decades.
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He called President Trump to tell him Sunday night.
"Before I could say a word, he said to me, well Marsha got elected, that's good," said Alexander. "He said, 'Let's talk about you serving for another 20 years.' And I said, 'Mr. President, I'm calling to tell you I'm not not going to run for re-election,' and he said 'Well why would you do that?' I said, 'I thought two terms as Governor and three terms as a US senator were enough.'"
President Trump vowed to work with the 78-year-old Alexander for the next two years to help the country.
Inside Tennessee panelist and Republican Susan Richardson-Williams says Alexander has helped Tennessee significantly.
"Certainly the Smokies and the environment, air quality, all of that is something he's been very interested in," Richardson-Williams said. "You name it--Lamar has had a hand in it. The good thing about him: he's very bright, and he does work across the aisle to get things accomplished."
Pilot Flying J founder Jim Haslam served as Alexander's financial director early in his political career.
"Talk to Thomas Zacharia, the head of Oak Ridge National Lab," Haslam said. "He'll tell you what an advocate Lamar has been for the Oak Ridge National Lab. Or talk to the University, they'll tell you. Lamar has just been so strong on the things that are so important."
As far as a replacement? Alexander has only heard some names.
"Governor [Bill] Haslam, of course, very popular in Tennessee, Ambassador Bill Hagerty from Gallatin is very close to President Trump, he was head of his transition team," Alexander said. "Then we've got a whole group of Congressmen who are talented."
Jim Haslam declined to comment on how Alexander's announcement affects, if at all, his son's future.
Bill Haslam is nearing the end of his second term as governor.
He considered running for Senator Bob Corker's seat, but ultimately decided against it.