As long as the moderator has his politics and his own positions on the issues, then, that moderator can never be expected to be fair to the debater whose politics do not coincide with his.
FOX news talked up Wallace’s fairness and balance, weeks before the debate, and even after the debate, continue to defend him. FOX could have made a much better choice for moderating duties; Wallace is not a moderator, and chose to be a defender of Biden in the debate.