In appearances with the governor in Burbank and Oakland, the Arizona senator urged California voters to support the four initiatives backed by Schwarzenegger on the special election ballot.
"I have campaigned for reform efforts all over the country," McCain said. "What happens in California has significant effect in states like mine that are nearby. It's just a reality."
Schwarzenegger, a Republican, is pushing a quartet of proposals that he has described as medicine for a sickly government. They would cap state spending, strip lawmakers of the power to draw political boundaries, lengthen the probationary period for teachers from two years to five, and require public employee unions to get members' permission before dues could be used for political purposes.
McCain said he supported the proposal that would take the power to draw district boundaries away from legislators and give it to a panel of retired judges.
"We need more competitive races," said McCain, known nationally for his efforts to retool the campaign-finance system. "We need the voice of moderation."
McCain's visit comes at a crucial time for Schwarzenegger. With the election less than a month away, three of the four initiatives he supports are trailing in polls, and many Californians have turned cold on his leadership.
Roger Salazar, a consultant to the California Democratic Party, said the Arizona senator would do little to help Schwarzenegger's cause. "Californians can make up their own minds," he said.
In Burbank, about two dozen union members and activists protested outside the hotel where the Republicans spoke. About a hundred protesters stood outside the Oakland gathering.
In San Francisco, U.S. Sen. Barbara Boxer (search) and state Treasurer Phil Angelides spoke out Monday against another issue on the Nov. 8 ballot that would require doctors to notify parents or guardians before performing an abortion on a minor.
The Democrats said the proposed amendment to the state constitution could eventually erode women's reproductive rights.
Under the proposal, girls would not need consent from an adult to get an abortion. But sponsors hope the notification requirement would reduce California's teen abortion rate, the fourth-highest in the country, by involving parents in the decision.
Schwarzenegger has already endorsed measure.