LAS VEGAS – A union with ties to Democrat Hillary Rodham Clinton failed in court Thursday to prevent casino workers from caucusing at special precincts on the Las Vegas strip.

The ruling by U.S. District Court Judge James Mahan was presumed to be a boost for Clinton rival Barack Obama in the Democratic presidential caucuses Saturday because he has been endorsed by the union representing many of the shift workers who will be able to use the precincts.

“State Democrats have a First Amendment right to association, to assemble and to set their own rules,” Mahan said.

Nevada’s Democratic Party approved creation of the precincts to make it easier for housekeepers, waitresses and bellhops to caucus during the day near work rather than have to do so in their neighborhoods.

The state teachers union, which has ties to Clinton, brought the suit against the special precincts shortly after local 226 of the Culinary Workers Union endorsed Obama for the Democratic nomination. The union is the largest in Nevada, with 60,000 members. The Clinton campaign said it was not involved in the suit.

The suit contended party rules allowing the precincts gave too much power to the casino workers and violated federal equal protection guarantees.

But the judge said, “We aren’t voting here, we’re caucusing. That’s something that parties decide.”

He said it is “up to the national party and the state party to promulgate these rules and enforce them.”

The Democratic National Committee ratified the state party’s rules in August.

Campaigning in San Francisco, Obama welcomed the judge’s decision, saying, “Any alternation would have disenfranchised maids, dishwashers, bellhops, people who work on the strip. Some of the people who set up the rules apparently didn’t think that we would be as competitive as we were and tried to change at the last minute.”

Nevada State Education Association President Lynn Warne denied the case was linked to the Clinton campaign and said there would be no appeal to the 9th U.S. Circuit Court of Appeals in San Francisco.

In a statement, the Clinton campaign pointed out that other voters won’t receive the same advantages as the bellhops and waitresses along the strip.

“Make no mistake,” the statement said, “the current system that prohibits some shift workers from being able to participate, while allowing others to do so, would seem to benefit other campaigns. More importantly, it is unfair.”

Associated Press Writer Kathleen Hennessey contributed to this report