JEFFERSON CITY, Mo. >> At his suburban St. Louis home, Brett Koenig can pull out his smartphone and open a sports betting app. But he can’t place a bet. He is blocked by a pop-up message noting he is not in a legal location.

Missouri is one of a dozen states where sports wagering remains illegal more than five years after the U.S. Supreme Court cleared the way for states to adopt it.

“It just seems silly that everyone else can do it and we can’t,” said Koenig, who has launched a social media campaign called “Let MO Play” to rally support for legal sports betting in his home state.

Other states have reaped a total of over $4 billion of taxes from more than $280 billion wagered on sports since 2018. Vermont will become the latest to accept sports bets, starting Jan. 11, But the odds for expansion to additional states appear iffy in 2024 because of political resistance and the sometimes competing financial interests of existing gambling operators.

“The handful of states yet to legalize are last for a reason: They all have multiple obstacles,” said Becca Giden, policy director at Eilers & Krejcik Gaming, a California-based consulting firm.

After a “whirlwind” of expansion, the playing field for further sports betting has narrowed to a group of states where various stakeholders all “want to kind of maximize what they get out of the legalization framework,” said Chris Cylke, senior vice president of government relations at the American Gaming Association, which represents the industry. “So that can create some friction.”

The states where sports betting remains illegal are Alabama, Alaska, California, Georgia, Hawaii, Idaho, Minnesota, Missouri, Oklahoma, South Carolina, Texas and Utah.

California and Texas, the nation’s two most populous states, would be the biggest prizes for sports bettors. But neither appear particularly likely to adopt it in 2024.

Voters in California last year overwhelmingly defeated two rival sports betting initiatives following a record $463 million raised by supporters and opponents. The advertising barrage was fueled by divisions among online gaming companies, tribal casinos and horse tracks. Those tensions have continued, with Native American tribes objecting to a new sports betting initiative that is seeking signatures to appear on the 2024 ballot.

The proposed sale of the Dallas Mavericks basketball team to a politically active family that runs the Las Vegas Sands casino company has raised speculation of a bigger push for legal sports betting in Texas. But the state Legislature is not in regular session in 2024, and Texas has no means of placing citizen initiatives on the ballot.

Neighboring Oklahoma already has scores of casinos run by tribes. Republican Gov. Kevin Stitt announced a plan in November to allow in-person sports betting at tribal casinos and online sports wagering through platforms licensed by the state. But his plan doesn’t appear to have support from tribes, with whom Stitt has been feuding.

Minnesota is perhaps the next likeliest state to authorize sports betting, but that probably would require a bipartisan vote in the Senate, where Democrats hold a slim one-seat advantage over Republicans. Lawmakers this past year struggled to resolve differences between tribal casinos, which want exclusive rights over online and in-person sports betting, and horse racing tracks, which also want a greater share of the gambling market. But they will try again.

“From the perspective of the tribes, the moment is now, and they’d like to see it done this year,” said Democratic state Sen. Matt Klein, a sponsor of sports betting legislation.

Efforts to legalize sports betting in Missouri have repeatedly stalled in the state Senate, where Republican Sen. Denny Hoskins insists it must be paired with the regulation of legally questionable slot-machine-style video games that have popped up in convenience stores and truck stops. Casinos oppose that.

Online sports wagering companies, casinos, professional sports teams and video gaming terminal interests have combined to hire about 80 lobbyists in Missouri.

The St. Louis Cardinals also are leading a coalition of the state’s professional sports teams proposing an initiative petition to put sports betting on the November ballot. But Senate President Pro Tem Caleb Rowden doubts the prospects of both the initiative petition and legislation, bemoaning that Missouri may “lose out on probably some fairly significant economic activity.”

Data suggests Missourians are interested in sports betting. From mid-June to mid-December, the technology firm GeoComply Solutions processed over 13.5 million location checks from 280,000 devices located in Missouri attempting to access mobile sports betting sites. About 48% were trying to use sportsbooks in Kansas, and 40% in Illinois. They were blocked from doing so.

When Koenig wants to bet on sports, he drives 45 minutes from his Missouri home to Illinois. He is not alone.

GeoComply processed 42,000 location checks from 1,900 online sports betting accounts that traveled from Missouri to an Illinois border town in the past six months. When the Kansas City Chiefs hosted the Buffalo Bills on Dec. 10, GeoComply tallied 786 location checks from 570 sportsbook accounts traveling from Missouri border towns into Kansas.

“It’s very easy for people to cross over, place their bets and then return to their home and watch the game,” GeoComply spokesman John Pappas said. “We see this thousands of times a day, a week, in any given state where it’s not legal.”

In Georgia, Republican Gov. Brian Kemp has expressed an openness to legalizing sports betting. But the effort stalled this past year when the Senate rejected a proposed constitutional amendment that would have let voters decide the issue. The debate is complex because proponents of casinos and horse racing want to leverage sports wagering to also legalize those forms of gambling.

Though still a toss-up, Georgia may be the most realistic candidate to authorize sports betting in 2024, Giden said. She expects a well-funded lobbying effort from the likes of online betting operators and sports teams.

To legally bet on sports in Alabama also would require a constitutional amendment approved by voters. In the Legislature, sports wagering proposals have become intertwined with broader efforts to expand gambling beyond the current tribal casinos, dog racing tracks and charitable bingo operators. None have been successful yet.

Republican state Sen. Greg Albritton said some lawmakers are working on new gambling legislation that would include casinos, a lottery and sports betting.

“Whatever happens, if I have my way, this issue will be debated this year,” he said.