U.S. Sen. Dianne Feinstein canceled a Sunday appearance at a gun control rally in Orange County.
Feinstein's campaign manager Jeff Millman says she is getting over a cold.
She was scheduled to speak Sunday evening at an event alongside student activists from the Florida high school where 17 people were killed in February. Gun control is one of Feinstein's signature issues. She authored the now-expired 1994 assault weapons ban.
Feinstein's most recent event was on Friday in Silicon Valley. Millman says she has an event planned Monday in the Bay Area but did not provide immediate details.
Feinstein faces a challenge from state Sen. Kevin de Leon, a fellow Democrat.
At 85 she is the oldest U.S. senator. De Leon has repeatedly called for a "new voice" in Washington but has not directly focused on her age.