It’s a good bet sports gambling soon will be allowed at tribal casinos. What’s next?

I bet I can finish writing this column in the next hour. Anyone want to take up the other side of that bet?

That traffic light up ahead: What’s the over/under on the number of cars the left-turn signal will let through before changing from green to red?

Who ya got for the Democratic nominee for president? The Academy Award for best motion picture? The Nobel Peace Prize?

Or, for a really interesting prop bet, how long before Washington goes all in on “bet anywhere, any time on anything” gambling?

The arc of history certainly seems to be bending that way, with the current legislative session’s debate over allowing sports gambling at tribal casinos being merely one point on that long journey. The enabling legislation (the latest version designated ESHB 2638) already has passed the House and this past week was under review in Senate committee.

The specific legislation at present is a sort-of, tentative step into sports gambling, which would be limited to on-site betting at tribal casinos. That, not surprisingly, is a major point of contention, with other parties eyeing the amount of money available and wanting a piece of it.

But then, what would be surprising about that? Large quantities of money have often proven to be significant persuaders of public and official attitudes.

Society has long had a conflicted and complex view of gambling, condemning it as a sin even as it indulges in the activity.. One of the most famous quotes in a movie replete with them is these days employed to depict all sorts of public hypocrisy: Capt. Renault proclaiming in “Casablanca” that he is “shocked, shocked to find that gambling is going on in here,” just as he is presented with his winnings.

Thus gambling was, in this country at least, officially confined to the horse race tracks and out-of-the-way venues like Las Vegas (or in low-stakes games like bingo, card rooms and punch boards), and unofficially nearly ubiquitous in everything from the corner bookie to the neighborhood numbers rackets to office pools and parlay cards.

Then some of the bolder officials took a look around and came to some conclusions. 1) Gambling is going to go on no matter how much we pontificate or try to prevent it. 2) As long as it does, we might as well get a cut of the action.

So states set up lotteries, authorized off-track wagering, allowed the expansion of casinos and have moved on to the next frontier — sports betting.

Perhaps the most dramatic transformation of attitudes can be found on the part of the professional sports leagues, which once vehemently resisted the notion of gambling on their contests to preserve the purity of the game, to the point of threatening to withhold franchises and events from cities and states that allowed it.

Now Las Vegas has an NHL team and is getting an NFL team. The NFL is looking at ways of officially partnering with casinos and betting operations, to the point of setting up “betting lounges” at stadiums (no betting windows, though. Yet.).

Given the momentum behind sports betting, the specifics of this year’s legislation are a relatively minor point. More interesting are these questions:

▪ What comes next? And when? It’s almost inevitable that there will be some sort of expansion. When has something, once made legal, been taken off the table? (Come to think of it, that does happen. Think of plastic bags and straws. Cigarettes sure seem headed that way.)

Once the tribes get sports betting, the campaign to allow others in on that business will intensify, as will the pressure to permit online gambling. How about at stadiums and arenas where the contests are played? After all, if you can bet on the horses at a race track, why not bet on the Mariners game at T-Mobile Park.

▪ Does sports betting have a business cycle? Is it recession-proof? The same questions could be asked of lots of businesses that have grown during the recovery but haven’t been tested by a downturn, which might prompt a closing of wallets for all but the most hardcore gamblers. The one consolation for sports-betting enterprises is that they don’t have to grow the total spent on gambling, they just have to take share away from other outlets.

▪ Does sports betting have a saturation point? The danger in the proliferation of ways for bettors to lay down wagers on games is that eventually the pool of money gets divided too many ways for all the would-be players to make money. The marijuana retailing business is likely to test this thesis first, and if it holds, there will be a period of consolidation.

▪ When’s the next big sports-gambling-related scandal? This year happens to be the 100th anniversary of the indictment of the Chicago Black Sox players for throwing the World Series the year before. Attempts to influence the outcome of contests — point shaving, fighters taking a dive — in order to gain a financial edge are a part of sports tradition, and legalizing sports betting won’t change that. There will be one.

The adage that death and taxes are the only sure things in life is accurate only as far as it goes. It’s also a certainty that people will gamble whether they’re allowed to or not. Will their behavior change if they’re given more legally approved channels for doing so? That’s a more uncertain proposition — but one the Legislature is about to put to the test.