There are forty senate districts in the California State Senate
; each senator serves for a four-year term. Elections are held on a staggered basis. Elections for senators from the even-numbered districts are all held in one year (in 2002, 2006, 2010, 2014, etc.) while elections for senators from the odd-numbered districts are held in the opposite election year (2000, 2004, 2008, 2012, 2016, etc.)
Ten of the twenty senators whose terms expire in 2012 are serving in their first term, and nine are in their second full four-year term.
Of the nine senators who are currently serving a final four-year term on the California State Senate before they are termed-out, four are Republicans and five are Democrats.
Serving in first term
Mark Leno (3-D), Lois Wolk (5-D), Mark DeSaulnier (7-D), Loni Hancock (9-D), Tony Strickland (19-R), Fran Pavley (21-D), Roderick Wright (25-D), Bob Huff (29-R), Mimi Walters (33-R)
Serving in second term
Dave Cox (1-R), Joe Simitian (11-D), Elaine Alquist (13-D), George Runner (17-R), Carol Liu (21-D), Alan Lowenthal (27-D), Robert Dutton (31-R), Christine Kehoe (39-D)
Tom Harman (35-R) was elected in a special election in 2006 and then re-elected in 2008.