Former Maricopa County Sheriff Joe Arpaio raised the possibility that Sen. Jeff Flake, R-Ariz., may have committed treason by sharply criticizing President Donald Trump this week.

Flake spoke on the Senate floor Wednesday and compared Trump to former Russian dictator Josef Stalin. He is not running for re-election this year and Arpaio is campaigning for the seat.

"I don't know if Sen. Flake should make some comments against our commander-in-chief. I'm not saying, it could be considered by some a borderline treason-type situation. I'm not accusing him of that," Arpaio told Arizona TV station CBS 5.

"You gotta be careful when you blast the president on international issues."

The reporter then informed Arpaio that Americans have the right to criticize their president and government.

"Within reason," Arpaio replied.

It was reported last week that Arpaio is running for Flake's seat. The 85-year-old served as Maricopa County sheriff from 1993-2017. Last summer, he was convicted of contempt of court stemming from allegations that his department used racial profiling practices.

Trump pardoned Arpaio in August.