In 2012, billionaire casino mogul Sheldon Adelson and his wife spent at least $100 million backing conservative candidates. Via super PACs, he poured at least $20 million into Newt Gingrich's failed presidential campaign and contributed another $30 million to the Republicans' eventual nominee, Mitt Romney. (He also gave $23 million to Karl Rove's conservative PAC American Crossroads and $1.5 million to a PAC supporting George Allen's unsuccessful Senate run in Virginia.) If you factor in all the candidates, causes, and PACs he funded that election, Adelson easily set a record for the most money donated in a single cycle.

That dismal track record isn't stopping Adelson from wading into another political battle that sits squarely at the intersection of government regulation and his business interests. The Washington Post reported this morning that he is getting ready to roll out a public campaign of his own to stop the spread of online gambling. His chief concern? That betting online could be detrimental to children and the poor. Already he's hired three high-profile spokespeople — Wellington Webb, a former mayor of Denver, Blanche Lincoln, a former Arkansas senator, and George Pataki, a former New York governor — and is dispatching teams of public relations experts to state capitals to lobby against it.

Even if you take Adelson at his word that he's worried about the effect internet gaming will have on children and not his bottom line, it appears as though he is about to take on another losing issue in a fight that will come with a high price tag. It's not clear yet how much Adelson will spend to try to halt the spread of online gambling, but he's up against most of his casino competitors, several states, and a handful of federal lawmakers from both parties. Needless to say, he isn't the only one with deep pockets in this fight.

There is serious money at stake here. Industry analysts believe that the revenue from legal online gambling could top $600 million next year. By 2020, that figure could climb to $9 billion. (The American Gaming Association estimates that there are about 1,700 offshore sites that take online bets, bringing in somewhere between $4 billion and $6 billion a year.)

But it's more likely that Adelson's Coalition to Stop Internet Gambling will find its stiffest resistance not from rival gaming companies who want in on that revenue stream, but from nearly destitute state governments that are increasingly turning to taxes on gambling as a way to make up for their budget shortfalls. Earlier this month, New York voters approved a plan to build seven new casinos. Last year, Maryland decided to allow table games like poker and blackjack at its casinos. Migrating online is a logical next step for these states, and already New Jersey, Nevada, and Delaware have passed laws legalizing the practice. California and Pennsylvania as well as a dozen other states may soon be added to that list.

Online gambling has been a contentious issue for the better part of the last decade. In 2006, Congress made it illegal for people to use credit cards to place wagers online, but since then the tide has been turning in favor of those who want to legalize, regulate, and tax internet betting. In late 2011, the Justice Department clarified that there was no federal prohibition on online gambling. Since then, two bills have been introduced in the House of Representatives that would allow for online gaming. The most recent one, sponsored by Rep. Peter King (R-N.Y.) in 2013, would legalize it in all forms except for sports gambling.

So the cards are once again stacked against Sheldon Adelson. The only real question is, how much of his own money will he sink into his latest bid before he decides to fold?