Democrat Francine Busby is set to announce later this week that she will run again next year in California’s 50th district, a seat currently held by Rep. Brian Bilbray (R).Busby rose to prominence as the Democratic nominee in the hard-fought and extremely expensive 2006 special election to replace disgraced ex-Rep. Duke Cunningham (R), who was convicted and sent to prison for evading taxes and taking more than $2 million in bribes.Busby won 44 percent in the initial all-party primary, but she fell to Bilbray in the second round of balloting — taking 45 percent to his 50 percent. She ran again in the 2006 November general election, losing by 10 points.In a statement, Busby noted the changing demographics of the San Diego-area district as evidenced by President Barack Obama’s 51 percent to 47 percent victory in the 50th last year.“Voters called for change in 2008 when they elected Barack Obama,— Busby said in a statement. “Bilbray didn’t heed the message. He played a reckless, cruel game of politics with the lives of struggling San Diegans when he voted no on Recovery and Reimbursement Act that would bring millions of federal stimulus dollars into our economy.—National Democrats have been increasingly optimistic about new opportunities to put GOP-held seats in play in the Golden State in 2010, using Obama’s performance in a handful of districts as their barometer.Busby, who has served as a Cardiff school board district trustee, will kick off her campaign at an announcement Thursday in Encinitas.