The service at Brown Chapel African Methodist Episcopal Church in Alabama was held to commemorate the 52nd anniversary of the "Bloody Sunday" march that erupted in police violence on Selma's Edmund Pettus Bridge, according to a video posted to Rev. William Barber's Facebook page.
Barber, who is president and senior lecturer of Repairers of the Breach, and church-goers walked out after Merrill spoke in support of Alabama's voter ID law, according to the video's caption.
"We can't be polite about this. We can't be casual or cavalier," Barber told a reporter. "We have more voter suppression in recent years than we've seen since Jim Crow."
He said that Merrill's promotion of the voter ID law was "another lie."
"I don't care if you came as secretary of state, to stand up and tell another lie, to push the lie of voter ID and confuse people, normalize it, on a day when the nation is watching," Barber said. "You cannot come and stand in that pulpit and promote a voter suppression tactic and then we just sit there."
He said that "democracy is at stake."
"You cannot have a democracy where voter suppression is normalized, where people will politely let people say to them what they're doing, in their face and in their church, and it's okay," Barber said. "To respect injustice is to be a part of it."
"If you undermine voting," he added, "everything else falls apart."
In October 2015, Merrill insisted that the closure of 31 driver's license offices — many in majority black counties — would not prevent residents from obtaining the government-issued photo ID required to vote in Alabama.
Before the 2016 election, he went on to blast automatic voter registration, saying that it would "cheapen" the work of civil rights leaders.
"If you’re too sorry or lazy to get up off of your rear and to go register to vote, or to register electronically, and then to go vote, then you don’t deserve that privilege," Merrill said.
He then lashed out at criticism of Alabama's registration process and threatened to prosecute a filmmaker who described registering to vote in the state as "complex and complicated."
Merrill threatened to prosecute Brian Jenkins if he was registered in two states, even though Jenkins never claimed to be registered in Alabama.
— John Merrill (@JohnHMerrill) November 3, 2016
Alabama's secretary of state is no stranger to controversial comments. In April 2016, Merrill criticized calls for the removal of Confederate symbols from government buildings. He called the symbols a monument to "a way of life that makes us special and unique."