SAN FRANCISCO » Warned of dangers and legal chaos, California voters rejected yesterday a measure that would have made their state the first to legalize the use and sale of marijuana.

The spirited campaign over Proposition 19 had pitted the state’s political and law enforcement establishment against determined activists seeking to end the prohibition of pot.

It was by far the highest-profile of the 160 ballot measures being decided in 37 states. Other measures dealt with abortion, tax cuts and health care reform.

On a night of conservative advances in much of the country, Massachusetts voters spurned a chance to cut their taxes — rejecting a proposal to lower the state sales tax to 3 percent from 6.25 percent. Critics said the cut would have forced the state to slash $2.5 billion in services, including local aid to cities and towns.

In Oklahoma, voters overwhelmingly passed three measures that had dismayed some progressive and immigrants-rights groups. One makes English the state’s "common and unifying language"; another requires a government-issued photo ID in order to vote; and the third prohibits state courts from considering international law or Islamic law when deciding cases.

California’s marijuana proposal — titled the Regulate, Control and Tax Cannabis Act — would have allowed adults 21 and over to possess up to an ounce of pot, consume it in nonpublic places as long as no children were present and grow it in small private plots.

Proposition 19 also would have authorized local governments to permit commercial pot cultivation, as well as the sale and use of marijuana at licensed establishments.

Proponents pitched it as a sensible, though unprecedented, experiment that would provide much-needed revenue for the cash-strapped state, dent the drug-related violence in Mexico by causing pot prices to plummet, and reduce marijuana arrests that they say disproportionately target minority youth.

The state branches of the NAACP and the League of United Latin American Citizens endorsed it, as did several retired police chiefs. However, every major newspaper, both political parties, the two candidates for governor and all but a handful of leading politicians came out against it.

Federal officials said they would continue enforcing laws against marijuana possession and sales if the initiative had passed.

Even facing defeat, Prop 19 supporters said they were buoyed by a new Gallup poll showing that national support for legalizing marijuana has reached an all-time high of 46 percent. Gallup said majority support could come within a few years if recent trends continue.

In South Dakota, voters rejected a measure to legalize medical marijuana — a step already taken by California and 13 other states. A medical marijuana measure also was on Arizona’s ballot, and Oregon voters were deciding whether to expand the state’s current medical marijuana law by authorizing state-licensed dispensaries.

Among other notable ballot issues yesterday:

» Washington state’s voters repealed taxes on candy, soda and bottled water adopted by lawmakers last year — a move that could eliminate a projected $352 million in revenue over five years. Voters rejected a proposal to impose a state income tax on any income above $200,000, or $400,000 for couples.

» In the littlest state, voters chose to keep the longest formal name — opting to stay as Rhode Island and Providence Plantations, instead of just Rhode Island.

» In Illinois, where the two most recent former governors have been convicted on federal charges, voters approved an amendment that enables future governors to be recalled by popular vote.

» Oklahoma voters approved a proposed amendment aimed at nullifying the segment of the new federal health care law requiring people to have health insurance. Similar measures were on the ballots in Arizona and Colorado.

» In Colorado, political leaders of both major parties opposed three measures to ban borrowing for public works, cut the income tax and slash school district property taxes. Opponents said the proposals would cost the state $2.1 billion in revenue and eliminate tens of thousands of jobs.

» For the first time since the 1990s, there were no measures to ban same-sex marriage. But in Iowa, voters were deciding whether to oust three state Supreme Court justices who joined a unanimous 2009 ruling that legalized gay marriage there.

» Colorado voters were deciding on an anti-abortion "personhood" amendment — similar to one rejected in 2008 — that would give unborn fetuses human rights in the state constitution.

» California’s Proposition 23 would suspend the state’s landmark greenhouse gas emissions law until the jobless rate falls to 5.5 percent for a year. It is backed by out-of-state oil companies; foes include Gov. Arnold Schwarzenegger and alternative-energy entrepreneurs.

» An Arizona measure would ban affirmative action programs by state and local governments based on race, ethnicity or sex.