The ruling was unanimous and will be followed at some point by a written explanation for the decision, according to a brief order.
Business interests including the Arizona Chamber of Commerce sued the state in December after Prop 206 passed by 58-42, fighting the law on technicalities. They appealed after a Maricopa County Superior Court judge ruled that the law doesn't require the state to pay more to state contractors.
Both sides appeared before the Arizona Supreme Court last week during a hearing to make their case.
"It's fantastic," said Bill Scheel of Javelina public-relations firm, which ran the Prop 206 campaign on behalf of the union-sponsored Arizonans for Fair Wages and Healthy Families. "Knowing it prevailed, and unanimously prevailed, is very reassuring in terms of how working Arizonans are respected by the courts here."
The law raised the minimum wage in Arizona to $10 for this year. It'll go up to $12 in 2020. The law also forces employers to provide paid sick time to employees.
Scheel said there's no evidence the law has had a negative impact on jobs in Arizona.
While the fight for Prop 206 is over, Scheel said the Arizona Chamber of Commerce isn't "done."
He points out that the chamber is behind the effort at the Arizona Legislature to change the citizens' initiative process, making it much harder for voters to pass laws in the future.
"I think that's where the threat is now," he said.