The kabbalistic book "Shushan Sodot" explains that those Israelites who didn't believe that Moshe is ever returning from Mount Sinai didn't ask Aharon to build a "Golden Calf" for them. What they did was demanding a new leader taking over Moshe's position. Thus Aharon concluded that the "Golden Calf" would not be an item of idol - worship but only symbolizing a new leader. Aharon would have never guessed that, suddenly, the "Golden Calf" was becoming a new "G - d" for some of the Israelites.
Kabbalists such as the famous medieval Rabbi Yitzchak Luria teach that the Calf was a reincarnation and to bring about another reincarnation. Not only that but it also spoke to the people as soon as someone stuck a piece of paper into its mouth. One of the highest names of G - d was written on that piece of paper, formerly used by Moshe in order to lift up Joseph's coffin out of the Nile.