There are a lot of imaginary theories about what happened at the council of Nicea in 325 AD. There should be no theories, as we have clear records of what happened there. The council was convened by Roman emperor Constantine, who did not play a significant role, let alone vote on anything.
Eusebius' Ecclesiastical History Book 3, translated by Arthur Cushman McGiffert. Chapter 1. The Parts of the World in which the Apostles preached Christ.
