Voters in the nation’s most populous state will get a chance in November to unleash the massive new industry — and provide a jolt to other holdouts.

“California is the holy grail of U.S. sports betting markets,” said Daniel Wallach, a Florida-based attorney who has advised various players in burgeoning sports wagering states. “This is going to be a half-a-billion-dollar battle for control of the most lucrative betting market in the world.”

Thirty-three states and Washington, D.C. have authorized sports betting, birthing a sector expected to generate tens of billions of dollars in revenue once those markets are fully operative. The explosive growth follows two-and-a-half decades in which Congress gave Nevada an effective monopoly on athletic wagering in America.

If California legalizes, sports betting is likely to become legal everywhere in the U.S. “A lot of people basically think the rest of the country will legalize if California does,” said Oklahoma State University professor John Holden, who has testified as an expert witness as states consider gambling legislation.