While his opponent, Democrat Nick Leibham, airs ads telling U.S. Rep. Brian Bilbray (R-Carlsbad) that he "should be ashamed," the incumbent congressman has kept positive on TV with an ad highlighting his reformer credentials.

"Brian Bilbray has been a leading voice for ending our dependence on foreign oil and creating clean, alternative energy," a narrator says, "even before it was cool."

The narrator also emphasizes that "Bilbray went to Washington to end the culture of secrecy and corruption."

"Now he is fighting for taxpayers by demanding all financial rescue packages protect families and Main Street, not Wall Street," the narrator concludes.

Corruption is a particularly relevant topic in the 50th Congressional District, where former Congressman Randall "Duke" Cunningham once made national news for taking millions of dollars in bribes. Cunningham, who is now serving an eight-year prison sentence, resigned in November of 2005, and Bilbray won a special election to replace him five months later.

Although Bilbray has stayed positive with his TV ads, he has also been attacking Leibham for voting for the financial rescue package in a series of hard-hitting mailers.

ELSEWHERE on PolitickerCA.com:

• Leibham continues attacks with new ad
• Bilbray mailer focuses on Leibham’s alleged support of earmarks
• Retired general tries to set record straight for Bilbray
• Leibham pollster explains why Democrats can win CA-50