Five-term Democratic Rep. Diane Watson will retire at the end of this term, Fox News has learned. 

The 76-year-old California congresswoman represents parts of Los Angeles County and the city of Los Angeles and is known as a loyal Democrat. In a 2006 evaluation of voting records, National Journal ranked her as the most liberal member in Congress. President Obama won her district by 32 points in the 2008 election. 

Watson becomes the 12th House Democrat to announce his or her retirement. Seventeen Republicans have decided against seeking re-election, including Rep. Vern Ehlers, R-Mich., who announced his decision earlier Wednesday. 

More than 80 percent of registered voters in Watson's district are Democrats, and political handicappers would expect the seat to remain in Democratic hands this fall. 

Watson is a member of the Congressional Black Caucus. She served as a "superdelegate" for Hillary Clinton going into the 2008 Democratic National Convention in Denver, following the current secretary of state's unsuccessful presidential run. 

Before entering politics, Watson worked as a elementary school teacher and a school psychologist. Even though her district includes the University of Southern California, Watson earned her undergraduate degree from arch-rival UCLA and her doctorate in education at Claremont Graduate School. 

She was the first black woman ever elected to the Los Angeles School Unified Board and later served in the California State Senate.