In the years after Mr. Siegelman’s plan failed, there were crackdowns on the state’s electronic bingo halls; accusations of corruption, only a few of which were proven, including some against Mr. Siegelman; and an uproar when an influential Republican lawmaker floated the idea of legalizing some gambling instead of raising taxes.

Less than two years ago, a Republican governor who had been a Baptist deacon proposed a referendum on setting up a lottery, and even called a special session of the Legislature, but the effort stalled. Now, both the Republican governor, Kay Ivey, and her Democratic rival, Walt Maddox, say the state should hold a vote.

Still, there are limits: At least for now, the home of the storied Iron Bowl college football rivalry — the state all but freezes each year for the duel between Alabama and Auburn — seems far more likely to start a lottery than legalize sports betting.

No single theory has won out to explain why Alabama’s anti-gambling fervor may have ebbed.

Some see a creeping secularization in what has long been one of America’s most churchgoing states, or wonder whether voters and elected officials alike have simply grown exhausted by the issue. Others see rising voter frustration over how Alabamians wind up padding the budgets of other states when they cross borders to buy Powerball tickets or play blackjack.

And there is the reality that plenty of people who stay in Alabama are placing bets already. Illegal, untaxed gambling is thought to be widespread, and the state’s three tribal casinos, limited as they are in what they can offer, attract patrons from all over Alabama. A local minister was known to drive Harper Lee, the author of “To Kill a Mockingbird,” to one of them before she died in 2016.

Mr. Godfrey, the church lobbyist and executive director of the interdenominational Alabama Citizens Action Program, said the coalition against legalized gambling had fractured.