The chief rulers - Members of the Sanhedrin - Nicodemus, Joseph, and others like them.
Because of the Pharisees - The Pharisees were a majority of the council.
Did not confess him - Did not openly avow their belief that he was the Messiah. Two of them, however, did afterward evince their attachment to him. These were Joseph and Nicodemus, John 19:38-39. That Joseph was one of them appears from Mark 15:43; Luke 23:50-51.
Put out of the synagogue - Excommunicated. See the notes at John 9:22.