Just to recap:
On September 1st, Doug La Malfa resigned from the State Senate (at the end of the legislative session) in preparation for being sworn into Congress.
On December 3rd, Bob Filner resigned from Congress to become Mayor of San Diego.
On January 2nd, Gloria Negrete McLeod and Juan Vargas resigned from the State Senate to become Members of Congress. On the same day, Tony Cardenas resigned from the L.A. City Council for Congress.