After a high-profile spat with President-elect Trump last year, Gold Star father Khizr Khan has returned to the spotlight to argue against Alabama Republican Sen. Jeff Sessions’ nomination to be the next attorney general.

“I am writing to urge you, out of respect for the American values enshrined in the Constitution, not to confirm Sen. Jeff Sessions to be Attorney General of the United States,” Khan wrote in a letter to the members of the Senate Judiciary Committee released Monday by People for the American Way. “I am also well aware of the fact that the Republican Majority of this honorable Committee may confirm Sen. Sessions after an incomplete and less than thorough hearing which will compromise its moral authority in our legislative system.”