One of the most closely watched initiatives, Gov. Jerry Brown’s proposal to raise sales and income taxes to help balance the state budget, remained too close to call, as did measures to repeal the death penalty and require labeling on genetically engineered foods.

Those were among a slate of 11 weighty ballot measures facing California voters Tuesday.

Brown’s initiative, Proposition 30, asked voters to raise income taxes on those making more than $250,000 a year and sales taxes on everyone to help balance the state budget and avoid about $6 billion in cuts, mostly to schools.

The Democratic governor projected optimism as he addressed supporters at a Sacramento hotel Tuesday night, despite millions of outstanding ballots.

“I know a lot of people had some doubts, had some questions, about ‘Can you really go to the people and ask them to vote for a tax?’” Brown said. But he said people from diverse groups came together to support it. “A core reason that brought people together in support of Proposition 30 was a belief in our schools and our university and the capacity of the state government to make an investment that benefits all of us.”

The spending cuts are already built into this year’s state budget, and Democrats warned of dire results if the taxes were not approved, including some school districts that could shorten the school year by as many as three weeks.

Brown spent the final two weeks trying to remind voters of the choice, and Democrats toted his Welsh corgi, Sutter, around the state trying to boost enthusiasm. Recent public opinion polls showed the initiative falling below the 50 percent threshold needed for passage, but Brown’s supporters were focused on the 14 percent of likely voters who were undecided. They believed a few hundred thousand votes could push it over the top.

He faced competition from a rival proposal to broadly raise income taxes and send the money directly to public school districts. That initiative, Proposition 38, was funded by wealthy civil rights attorney Molly Munger, who topped all donors for the ballot measures, giving $44 million to her campaign.

Voters easily rejected that initiative, and Munger conceded at an election night party at the upscale Drago Centro restaurant in downtown Los Angeles.

“Obviously this is not the outcome we all hoped for but transformational change can take a long time and we all know that,” Munger told supporters. She congratulated Brown for a well-run campaign but her supporters seemed less enthusiastic, offering only a smattering of applause.

In all, the campaigns for and against the initiatives raised a whopping $372 million, according to MapLight, a nonpartisan research group that tracks political spending.

A hedge fund billionaire financed the campaign for a third tax measure that voters approved. Proposition 39 repeals a loophole pushed by Republicans in the Legislature in 2009 that allows out-of-state companies to set their own tax rate and put California-based companies at a disadvantage. The $1 billion a year it is forecast to raise would be split for the first five years between the state general fund and energy efficiency improvements for public buildings. After five years, all the revenue would be directed to the state general fund.

Unions and other Democratic interests have spent at least $75 million in an attempt to defeat Proposition 32, an initiative aimed at thwarting the political influence of unions. Corporate interests and wealthy Republicans have spent as much as $60 million in favor of the initiative, with some of that money also going into the effort to defeat Brown’s tax initiative.

The anti-union initiative follows conflicts in Wisconsin, Ohio, Indiana and elsewhere where Republican efforts to weaken organized labor have produced protests and political tumult.

After a contentious last-minute legal fight that went to the state Supreme Court, it was revealed Monday that an $11 million donation to a group backing the anti-union initiative and opposing Brown’s tax plan came from two groups that have spent millions on conservative causes nationwide. The Arizona nonprofit that funneled the money into California declined to reveal the original source of the contribution, however.

A proposal to abolish the state’s death penalty was trailing. It would convert the sentences of the 726 inmates on California’s death row to life in prison without the possibility of parole, and a plan to revise California’s Three Strikes law to ensure that a final crime must be serious for felons to qualify.

Another contentious initiative that would require most genetically engineered food and produce sold in supermarkets and other outlets to be labeled was also trailing Tuesday. The GMO foods would be barred from calling themselves “natural” on their labels.

Voters easily approved new Senate district maps that were drawn for the first time by a voter-approved independent panel of citizens.

Other statewide propositions include revisions to the state budget process that would have lawmakers draft two-year spending plans, an attempt by an insurance magnate to give auto insurance companies more leeway in setting their rates.