The suspect is described as a man 25 to 35 years old, driving a black pick-up truck.
EXCLUSIVE: Newsom recall supporter suffers fractured skull after assault at rally in San Rafael
Police say he used a knife to cut down pro-recall banners on a pedestrian bridge over Highway 101 Sunday.
When confronted by rally organizers, police say the man knocked one of them to the ground and punched him.
A group in support of recalling Governor Gavin Newsom returned to Marin County Monday afternoon to sway the public into voting yes when polls open Tuesday.
RELATED: How the recall election of California Governor Gavin Newsom came to be
"The crime rate has been outrageous and we are seeing it ourselves in this group," said Melanie Morgan, the protest organizer. "We need Gavin to leave office immediately."
Morgan and her group of protestors returned Monday because they didn't want to be limited by the violent incident over the weekend.
"We don't want to be silenced," Morgan said. "We are here to make a statement that we want new leadership in California."
VIDEO: North Bay recall supporters back to rallying after group member's skull fractured in weekend assault