The president of an Alabama civil rights group is calling on Supreme Court Chief Justice Roy Moore to insist one of his top lawyers resign following a letter seemingly rebuking the governor for saying the state would follow the gay marriage law.

The call by the Southern Poverty Law Center for the resignation of Win Johnson came just hours after publication of the letter on AL.com. [See letter here.]

Johnson had sent a copy to the governor's legal adviser.

Richard Cohen, the president of SPLC, called on Moore to act immediately to "maintain the integrity of the Alabama judicial system."

"Chief Justice Moore should insist that Win Johnson, the director of the legal staff of the Administrative Office of Courts, resign his position immediately in light of the letter Mr. Johnson wrote in response to the United States Supreme Court's decision in the same-sex marriage case," Cohen said in a news release.

Alabama Chief Justice Roy Moore discusses the U.S. Supreme Court's same-sex marriage ruling Monday, June 29, 2015, in Montgomery, Ala. (Julie Bennett/jbennett@al.com)

"No one who urges resistance to the Supreme Court's ruling and who claims that '[p]ublic officials are ministers of God assigned the duty of punishing the wicked and protecting the righteous' should be serving as an official in the Alabama court system."

Among the passages in Johnson's letter:

Public official, what will you do? Will you stand up for the law of Alabama, for the people, for the weak and vulnerable, for the law of God? Or will you capitulate? Will you become complicit in the takeover by the wicked?

"I must follow the law," you say. Law? What law? There is no law anymore, there's just opinion. One day this, one day that. When the law becomes merely the opinion of a handful of people on the courts, there is no longer any law. There is tyranny. There is chaos. But there is no law.

Johnson told AL.com he wrote the letter out of a sense of frustration and that the letter comprises his thoughts and his alone.

"It is my letter. I wrote it alone," Johnson told AL.com. "No one else helped me. No one else read it before I sent it. No one approved it."