If you’re a gambling man or woman (and two of this fall’s seven California ballot propositions are about gambling), don’t bet the house against either of November’s Propositions 26 or 27.

These competing initiatives aim to legalize what once was criminal in this state. Legalizing onetime vices seems to have become a ballot-box favorite. The recent history of marijuana laws makes this clear, as voters first approved medical marijuana and later passed full recreational use of marijuana, to the point where it’s now hard to find a city or town without at least one cannabis dispensary.

The history of legal gambling in California is only slightly less telling. Voters in 2000 approved gambling on once-poor and desolate Native American reservations by an overwhelming 65-to-35% margin. They later drew a line and in 2004 refused to allow slot machines in urban card rooms and horse race tracks. In 2008, though, tribal compacts vastly expanding the number of slot machines on some reservations were approved easily.

Now come Props. 26 and 27, both aiming to legalize sports betting, a huge pastime from which Californians have been formally excluded. This still sends many thousands from our state to Nevada for live betting and onto illicit offshore websites for online wagers.

It’s still unclear what would happen if both initiatives pass. If there’s a precedent here, it could be the 1978 battle between the Prop. 13 property tax limits and milder limits in the rival Prop. 10. In that case, both passed, with 13 getting more votes and standing as untouchable law ever since.

The betting initiatives differ widely: Prop. 26 allows sports betting but only in person at casinos on semi-sovereign reservations and at four horse race tracks. It would also let casino tribes sue cardrooms over some games they offer, while allowing dice games and roulette at Native American casinos.

Meanwhile, Prop. 27, backed by online giants like FanDuel, DraftKings and BetMGM, legalizes online sports betting but would see the big operators each partner with American Indian tribes. Fully 85% of tax revenue produced from this would be earmarked for housing and to help solve homelessness.

Both measures provide avenues for almost unlimited growth of the interest groups behind them. It’s hard to see how they could co-exist, so the strong likelihood is for drawn-out legal battles over which one will govern if both pass.

So far, more than five dozen casino tribes are backing Prop. 26, which they see as their ticket to even more prosperity than they now enjoy. Most likely, more Native Americans would gain wealth under 26 than with 27, where the bulk of the money would go to the big gaming companies and a relative pittance to aid the unhoused.

The measures promise to make new money for many tribes that already rake in plenty, but the measures contain precious little to protect gambling addicts from losing whatever savings they may have. Today’s tribal gambling, confined for the most part to reservations, also does little to protect gamblers from addiction. At least now, however, they usually must go to tribal lands to engage in their habit.

Cardroom operators, longtime exploiters of loopholes in restrictive state laws, complain that if Prop. 26 passes it will prevent them from ever getting into games they now cannot run but which remain potential sources of riches. Their committee, with the pious-sounding name “Taxpayers against Special Interest Monopolies,” says 26 would “guarantee tribal casinos a near-monopoly on all gaming in California, adding roulette, craps and sports wagering to their current monopoly on slot machines.”

All this leaves little doubt that we’re seeing a contest between heavily monied interests over who will become the most wealthy. That’s why, having raised more than $300 million before July Fourth, this campaign will likely become the most expensive state electoral contest ever of any type.

The healthiest response from voters would be to reject both measures, but given the pent-up demand for sports betting in California and voters’ prior approval of things long considered vices, that’s not likely to happen. That means big-time sports betting will soon arrive here, with a corps of lawyers likely to decide its eventual shape and scope.

Tom D. Elias can be reached at [email protected]. To read more of his columns, visit californiafocus.net online.