Under a torrent of criticism for barring professors from testifying in a voting-rights case, the University of Florida had an explanation: This wasn’t about free speech or academic freedom, university officials said in October; it was about professors doing outside paid work that was against the university’s interest. But what if a professor were to go on unpaid leave to do that work?

More than two weeks before the controversy spilled into public view, courtesy of The New York Times, one of the professors seeking permission to testify suggested to his dean that he step away without pay from his university duties to mitigate any conflict, emails obtained by The Chronicle show. On October 12, Michael McDonald, a political-science professor, proposed the option to David E. Richardson, dean of the College of Liberal Arts and Sciences: “If my outside activity approval is denied,” McDonald wrote, “I would like to know my options, such as taking an immediate unpaid leave from the university during the duration of my participation in the litigation.”

The night before, McDonald explained, he had learned that the university had rejected a request from Daniel A. Smith, his colleague in political science, to serve as an expert witness in the same case. McDonald, whose research focuses on elections, told his dean he felt duty-bound to participate in the lawsuit brought by the League of Women Voters and other nonprofit organizations, who are challenging a new Florida law that critics say will make voting more difficult for poor people and minorities.

“I swore an oath to uphold the Florida constitution,” McDonald wrote, “and I therefore feel that it is my duty to be involved in this litigation to ensure that plaintiffs’ complaints have a fair hearing in court, a key foundation of our democratic principles as a nation.”

Richardson acknowledged the email and said he would get back to McDonald “asap.”

The next day, Gary Wimsett, the university’s assistant vice president for conflicts of interest, denied McDonald’s request to participate in the case. “As UF is a state actor, litigation against the state is adverse to UF’s interest,” Wimsett wrote.