In 70 C.E., the temple was destroyed, the high priesthood and the sanhedrin ceased to exist, and the priests lost not only their jobs, but also the institutional base of their power. The Jewish community of the land of Israel no longer had a recognized social elite or “establishment,” and the Jews of the diaspora no longer had a center that bound them together. This was the vacuum the rabbis tried to fill. Ultimately, they succeeded, but victory was gained only after a struggle. The rabbis were opposed by various segments among the wealthy and the priesthood, and by the bulk of the masses in both Palestine and the diaspora. The local aristocracies, especially in the cities, were not going to subject themselves voluntarily to the hegemony of a new power group; the priests still thought of themselves as the leaders of the people; and the masses were indifferent to many aspects of rabbinic piety. The rabbis triumphed over their opponents among the aristocracy and the priesthood by absorbing them into their midst, or at least coming to terms with them. The rabbis triumphed over the indifference of the masses by gradually gaining control of the schools and the synagogues. The exact date of the triumph is hard to determine, but it was not earlier than the seventh century C.E.
Shaye J.D. Cohen, From the Maccabees to the Mishnah (Philadelphia: The Westminster Press, 1987), 221.