Dunn, who ran a government relations firm, was undergoing surgery Monday to repair an aortic aneurysm.
He was recommended for the voting commission by the Republican secretary of state of Arkansas, who has a working relationship with Kansas Secretary of State Kris Kobach (R), the vice chairman of the commission.
“I think they were looking for a Southern Democrat to serve on the commission for some diversity,” Dunn said in an interview in July, before the panel’s first meeting.
Dunn said he was skeptical of Trump’s claim about losing the popular vote because of illegal voting and of claims of widespread voter fraud more broadly. But, he added, “I’m certainly open to considering what makes people feel that way.”
On Tuesday, fellow commissioner J. Christian Adams, a Republican, said on Twitter that he was saddened by Dunn’s passing.
“He was courageous to serve, courteous in his manners, and kind to everyone,” Adams said.