The pastor of Martin Luther King Jr.'s church urged Republican Sen. Johnny Isakson to disavow Donald Trump, launching one of the most aggressive attempts by Georgia Democrats to tie state GOP officeholders to their nominee's divisive rhetoric.

In an open letter to The Atlanta Journal-Constitution published Friday, the Rev. Raphael Warnock wrote that Trump "went over the cliff" when he suggested that Second Amendment supporters might stop Democrat Hillary Clinton. Trump later said his words were taken out of context.

You cannot embrace Dr. King's inclusive vision of "the beloved community" while endorsing Trump's hateful nation. You cannot remember Dr. King in January and dismember his legacy of love, justice and nonviolence in November. "There comes a time," King said, "When silence is betrayal." Senator, that time is now.

The reverend is no impartial observer. He flirted for months with a bid to challenge Isakson, was vetted by national Democrats and headlined Democratic Party fundraisers before deciding against a run. But as the leader of Ebenezer Baptist Church, the iconic Atlanta church where King was baptized and later pastored, his criticism holds symbolic resonance.

Isakson, who is seeking a third term in November, has endorsed Trump but repeatedly said his top focus is on getting re-elected to the U.S. Senate. In an interview on Thursday, Isakson said he stood by Trump and will make no apologies for his doings.

He was then asked if he still stood by Trump.

"I made one speech about that subject, in Cleveland, to our delegation to support our party," he said. "And I am supportive of our party and I'm a member of the party. That's my story and I'm sticking to it."

On Friday, Isakson was pressed by Doug Richards of WXIA on the “Second Amendment” remarks that Trump made in Wilmington, N.C., earlier this week:

Richards: Could you elaborate on that?

Isakson: No. I think that's a pretty definitive answer.