Veto Halts Bill for Jury Duty by Noncitizens in California Gov. Jerry Brown of California, center, on Thursday after signing into law a bill to grant driver's licenses to illegal immigrants. LOS ANGELES - Breaking with Democrats in the State Legislature, Gov. Jerry Brown vetoed a bill on 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, Mr. 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," Mr. 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 that 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 the legislation 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? Supporters said the measure would make it easier to assemble jury pools and grant legal immigrants a jury of their peers. While Mr. Brown faced pressure from fellow Democrats and advocates to sign the other bills giving immigrants new rights, there was no such campaign to convince him that allowing noncitizens to serve on juries was a pressing matter. By contrast, immigrants" rights groups held rallies and letter-writing campaigns urging Mr. Brown to sign the bill stopping local law enforcement agencies from detaining immigrants and transferring them to federal authorities unless they had committed certain serious crimes. Mr. Brown had vetoed similar legislation before, but his staff worked with immigrant advocates to devise a compromise that expands the kinds of crimes that would allow local authorities to hold on to arrested immigrants, like felony domestic violence and D.U.I. convictions. Under the new law, known as the Trust Act, unless immigrants have committed certain serious crimes, they cannot be detained past when they would otherwise become eligible for release. "While Washington waffles on immigration, California's forging ahead," Mr. Brown said in a statement announcing his approval of the law on Saturday. I'm not waiting. The batch of new laws also included one that would allow immigrants without legal status to be admitted to the state bar and practice law in California. There was little outcry about the governor's veto from immigrants" rights groups on Monday. Instead, they praised Mr. Brown for signing bills that they said amounted to "enormous momentum for immigrants." "We have really created a counterweight to other states like Arizona, that's really the story," said Jon Rodney, a spokesman for the California Immigrant Policy Center. Assemblyman Bob Wieckowski, a Democrat from the Bay Area and the chairman of the Judiciary Committee, which wrote the bill, said that he was disappointed in the veto and that while he did not plan to ask the Legislature to override it, he would introduce similar legislation next year. "I hope and believe this is just a temporary mistake," Mr. Wieckowski said of the veto. He has shown some enlightened thinking - he has just signed a bill that says even if you're undocumented you can go in front of a jury, so I hope he gets some more thoughts from constitutionally enlightened people around the country, and is convinced this is the right thing to do. He said he still believed barring immigrants from jury duty was a sign of prejudice, particularly in a state where legal permanent residents make up nearly 10 percent of the population. Assemblyman Rocky Chavez, a Republican from San Diego 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 debate over this bill attempted to create a social wedge in our communities over our justice system," Mr. Chavez said in a statement. "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."