LOS ANGELES -- Breaking with Democrats in the state Legislature, Gov. Jerry Brown vetoed a bill Monday that would have made California the first state to allow immigrants who are not citizens to serve on juries, saying that the responsibility should come only with citizenship.

As leader of a state with 3.5 million noncitizens who are legal permanent residents, Brown in recent weeks had signed into law numerous measures that put California at the vanguard of expanding immigrant rights, including granting driver's licenses to illegal immigrants. On Saturday, he signed several such bills, most prominently legislation stopping local law officers from detaining immigrants and transferring them to federal authorities unless they have committed certain serious crimes. And he agreed in August to let noncitizens monitor polls for elections.

But the governor drew the line at allowing legal immigrants to serve on juries. "Jury service, like voting, is quintessentially a prerogative and responsibility of citizenship," Brown said in a brief veto message.

"This bill would permit lawful permanent residents who are not citizens to serve on a jury. I don't think that's right."

Some legal scholars had said the measure raised profound questions about what rights and responsibilities belonged to citizens alone, and a number of newspapers published editorials urging the governor to veto the bill after it was approved by the Democratic-controlled Legislature, with most Republicans opposing it.

"It calls into question the very meaning of citizenship," the Sacramento Bee wrote in August, saying that it would provide an incentive to immigrants to avoid becoming citizens.

"Why should green-card holders become citizens if they can enjoy the rights of citizenship?" Assemblyman Bob Wieckowski, D-Fremont, chairman of the judiciary committee that wrote the bill, said he was disappointed in the veto and that while he would introduce similar legislation next year, he did not plan to ask the Legislature to override it.

Rocky Chavez, a San Diego Republican and the most vocal opponent of the jury duty bill, praised the governor for stopping a bill that "attempted to solve a problem that did not exist."

"The veto of this bill should be seen as a message that jury service is a responsibility of our citizens and the phrase 'jury of your peers' still means something in our criminal justice system."