Yes. Medvedev visited a synagogue in Birobidjan. See the Related Link below.
Answer 1There is no 'church' in Judaism. Judaism is a religion so there cannot be a separation from religion in Judaism.Answer 2It depends on what a person means by "Judaism". If the person is talking about the religion itself and its directions and exhortations of government, then no, there is no separation between church and state.However, all of the Jewish States or States led by Jews since the defeat of the Zealots nearly 1900 years ago (the Khazars, Birobidjan, UK under Disraeli, Modern Israel) have all had a separation between religion and state structure so that the law of the land was based on secular or universal legal principles and Judaism would be practiced at the will or disposition of the practitioner. In all four listed countries, being non-Jewish was not criminal nor would it subject a person to negative economic or social treatment.