(Adds detail from decision, reaction, background, byline)
By Alex Dobuzinskis
March 4 (Reuters) - A U.S. appeals court ruled on Monday on the side of day laborers seeking work in Arizona, upholding an injunction that bars the state from enforcing part of its immigration law that prohibits motorists from stopping traffic to pick up workers.
In the unanimous ruling, a three-judge panel of the San Francisco-based U.S. Ninth Circuit Court of Appeals found the state law, by criminalizing certain interactions between drivers and day laborers, went too far in restricting commercial free speech rights.
The court's decision is another blow to a tough 2010 Arizona law that sought to clamp down on illegal immigrants. The U.S. Supreme Court last year struck down key provisions of that law in a case brought by the Obama administration on grounds that the law clashed with the federal government's power to enforce U.S. laws on immigration.
The case before the appeals court stemmed from a civil rights lawsuit filed by immigrant and union groups, with help from attorneys from the Mexican American Legal Defense and Educational Fund and the American Civil Liberties Union.
The sections of the law in question made it a crime for a motorist to solicit or hire a day laborer if the car blocks traffic, and also prohibited any day laborer from entering a car that is obstructing traffic.
While attorneys for Arizona argued the state's intention was to promote traffic safety, Ninth Circuit Judge Raymond Fisher wrote in his opinion that the state could take other measures to achieve the same end.
The provisions of the immigration law dealing with day laborers and motorists appear to be "motivated by a desire to eliminate the livelihoods of undocumented immigrants," Fisher wrote.
"Laws that limit commercial speech must not be more extensive than necessary to serve a substantial government interest," he added.
GOVERNOR WEIGHING OPTIONS
The appeals court ruling upheld a February 2012 decision by a district judge in Arizona who granted a preliminary injunction against the provision.
Arizona's Republican Governor Jan Brewer touted the state's 2010 law cracking down on illegal immigration as a necessary response to what she described as the federal government's failure to control the border with Mexico. The border state of Arizona has seen a large influx of illegal immigrants.
Brewer spokesman Matthew Benson said the governor is conferring with her legal team to decide whether to appeal. "The governor thinks this is an important tool to give law enforcement," Benson said.
Omar Jadwat, supervising attorney with the ACLU Immigrants' Rights Project, called the ruling "another nail in the coffin" Arizona's tough immigration law.
The June 2012 decision by the U.S. Supreme Court struck down much that law as unconstitutional, including provisions that required immigrants to carry their papers at all times and banned illegal immigrants from soliciting work in public places.
A section of the law that has so far survived court challenges requires police in the state to check the immigration status of people they stop and suspect are in the country illegally, even if officers have stopped a person for minor offenses such as jay-walking.
In 2011, the Ninth Circuit struck down an ordinance by the California city of Redondo Beach that barred day laborers from gathering curbside to seek work.
"It is fundamentally wrong to criminalize work, to criminalize people who are looking for work to feed their loved ones," said Pablo Alvarado, director of the National Day Laborer Organizing Network.
His group was a co-counsel on the civil rights case challenging the Arizona law on day laborers. A 2004 survey by the group and university researchers found the nation had about 120,000 day laborers. (Reporting by Alex Dobuzinskis; Editing by Cynthia Johnston and Tim Dobbyn)