California also has one of the nation's highest unemployment rate and, recently, its highest gasoline prices.
The state budget Brown signed into law relies on the tax revenue that Proposition 30 will generate if voters approve it. Without it, Brown has warned California schools and colleges face $6 billion in automatic spending cuts.
Brown has also been largely absent from public view, despite saying that passing Proposition 30 is his top priority. His last public campaign event was Aug. 30. He did hold some separate gubernatorial events in September.
"He's got to explain it to people, because it's his measure. He needs to be out there explaining it," said Mark Baldassare, president of the Public Policy Institute of California.
The most recent public opinion polls have shown Proposition 30 with a slim majority of support before the attack ads began.
Molly Munger argues that taxpayers should be bailing out classrooms, not the state budget.
Her initiative was written so the tax revenue raised would avoid the Legislature and go directly to schools. In TV ads that began airing in September, her campaign has promoted its alternative to "Sacramento politicians," but polls show it has yet to persuade a majority of likely voters.
Brown's campaign waited until October to begin advertising on TV, then essentially adopted Proposition 38's tag line, saying "Sacramento politicians can't touch" the money. That claim is directly at odds with the independent legislative analysis of his initiative, statements the governor made this summer and his own description when he announced he had reach a compromise to put the initiative on the ballot.
"It's the tax program that balances the budget," he told The Associated Press in March. Brown declined to be interviewed about his initiative by the AP for this story.
Munger said she felt compelled to act after years of politicians failing to adequately fund California schools. She said her polling shows voters support more school spending, as long as the money doesn't go through the Legislature.
"It does seem to be a climate out there that is quite favorable for a message that the money will go directly to the schools and will skip Sacramento," Munger said in an interview last month.
Frustrated that Brown had co-opted her message, Munger began airing an attack ad this week that said, "Don't be misled by the politicians" showing a Proposition 30 sign crashing to the ground.