Former attorney general Jeff Sessions hit back at his former boss, President Trump, on Friday night in their long-running disagreement over whether Sessions should have recused himself from the Russia interference investigation that consumed the first two years of Trump’s presidency.

Sessions, who is running in Alabama to regain the Senate seat he left when he became Trump’s attorney general in 2017, faces a Republican primary runoff July 14 against former college football coach Tommy Tuberville.

Trump has backed Tuberville, in large part because he is still angry that Sessions stepped away from the Russia case in early 2017, shortly before special counsel Robert S. Mueller III was appointed to take over the investigation.

The president tweeted Friday evening: “3 years ago, after Jeff Sessions recused himself, the Fraudulent Mueller Scam began. Alabama, do not trust Jeff Sessions. He let our Country down.”

In his race to reclaim his Senate seat, Sessions has for months sought to appeal to Trump voters and show his loyalty to the president, despite Trump’s obvious displeasure with him.

On Friday night, Sessions decided to hit back at the president.

“Look, I know your anger, but recusal was required by law,” Sessions tweeted. “I did my duty, and you’re damn fortunate I did. It protected the rule of law & resulted in your exoneration. Your personal feelings don’t dictate who Alabama picks as their senator, the people of Alabama do.”

Tuberville has sought to exploit the bitter divisions between Trump and Sessions, declaring earlier in the week that Sessions threw Trump “to the wolves.” “When faced with supporting POTUS or running scared, Jeff Sessions chose the easy way out and recused himself. I won’t ever run from a fight in the U.S. Senate.”

Sessions recused himself from the Russia case in the wake of revelations that he had met in 2016 with Sergey Kislyak, then-Russian ambassador to the United States, despite having told senators during his confirmation hearing that he had not had communications with the Russians.

Trump erupted angrily when he learned of the recusal and never forgave Sessions, blaming that decision for the long-running investigation by Mueller that ended last year.

But even as Sessions pushed against the president’s criticism Friday, he also tried to argue that his policy positions are more in tune with Trump than Tuberville’s are.

“Tuberville’s a coward who is rightly too afraid to debate me,” Sessions tweeted at the president. “He says you’re wrong on China and trade. That’s not your agenda and it’s not mine or Alabama’s. I know Alabama. Tuberville doesn’t.”