Former Arkansas Gov. Mike Huckabee endorsed Sen. Lamar Alexander (R-Tenn.) in his re-election bid on Friday.
"He's been your governor, university president, America's secretary of education. He brought the automobile industry to Tennessee," Huckabee says in the online ad.
"Lamar Alexander is now a remarkable senator that Tennessee needs to return to office. Oh, and for anyone who wants to pick a fight with Lamar for supposedly not being conservative enough -- well, you might want to pick a fight with me first," the 2008 presidential contender concludes.
Alexander's main primary challenger, state Rep. Joe Carr (R), has attacked the senator on issues such as immigration reform and has received support from conservative radio talk show host Laura Ingraham. Ingraham also campaigned for Dave Brat, the Randolph-Macon College economics professor who beat House Majority Leader Eric Cantor (Va.) in his GOP primary earlier this month.
The GOP primary is scheduled for Aug. 7.
UPDATE: June 28, 11:20 a.m. -- The Carr campaign responded to the endorsement, saying: "We can only hope that Huckabee's support of Lamar Alexander will have the same impact it did when he backed David Dewhurst over Ted Cruz. This is the same person who said that Dewhurst was 'the only proven conservative' in that race. It just shows how desperate things are getting for Lamar Alexander when he has to promote someone who didn't even think Ted Cruz was 'a proven conservative.'"
ALSO ON HUFFPOST:
How will Trump’s administration impact you? Learn more