A 2018 Supreme Court decision opened the door to legal sports betting by voiding a federal law that prohibited it. Ever since, state after state — 32 so far — has legalized it and even the titans of professional sports, who once disdained betting on their games, are cashing in.

As this year’s professional football season begins, the National Football League is allowing gambling companies to advertise during its games, telling the Wall Street Journal “it made sense for us to really introduce sports betting in a thoughtful way into our national footprint.”

The NFL also selected Caesars Entertainment, DraftKings and FanDuel Group as partners who will pay many millions of dollars for the right to display NFL content on their betting sites.

So what about California?

Tribes Hope to Gain Control With Ballot Measure

Bills to legalize sports betting in the nation’s largest and richest market have kicked around the Legislature for several years but lawmakers have been unable to agree on a system that would please all of the contending gambling interests.

With deadlock in the Capitol, casino-owning tribes decided to grab control via a ballot initiative that’s already qualified for the 2022 ballot.

If approved, the measure would authorize betting on professional and collegiate sports at tribal-owned sites and four horse racing tracks — the latter an obvious gesture to a one-time rival to reduce potential opposition.

The measure also sanctions roulette and craps in tribal casinos and pointedly requires sports bets to be placed in person at the designated sites, thereby closing off on-line wagering until and unless the tribes want it.

The state’s poker parlors are opposing the measure, not only because it would create new competition for gamblers’ dollars but because it contains language that would subject them to increased state regulation.

Rival Initiative Fights Heavily Funded Tribe Campaign

It’s a David vs. Goliath situation because the tribes can throw almost unlimited funds into a campaign for the measure — in fact, they already have 10 times as much in their campaign treasury.

However, several cities that have poker parlors have filed a rival initiative that would also would authorize sports betting in Indian casinos and at racetracks but expand legalization to poker parlors, professional sports teams themselves and — most importantly — on-line betting operations.

The latter provision virtually invites the big on-line wagering corporations to pour millions of dollars into qualifying and passing the new measure and perhaps into opposing the tribal initiative. Whichever measure garners the most votes would prevail if their provisions conflict.

The stakes in this political showdown are immeasurably large — many billions of dollars in revenue. Will the tribes once again outfox the opposition or be compelled to share the bounty with their rivals? Or will a legislative compromise cancel the expensive ballot measure duel?