Sheldon Adelson in 2011. (Vincent Yu/AP)

Casino magnate Sheldon Adelson has spent hundreds of millions of dollars on Republican candidates around the country. Now, he’s turning his attention to statewide races — including a ballot initiative that would legalize medical marijuana in Florida.

Adelson has donated $2.5 million to oppose that measure, through a ballot initiative committee run by longtime friend Mel Sembler, the big-dollar Florida Republican activist.

It’s not Adelson’s first foray into Florida. He spent heavily for Gov. Rick Scott (R) until the two had a falling out over a key gambling contract in the state, according to the Tampa Bay Times.

Adelson isn’t the only big donor weighing in on weed. Trial lawyer John Morgan, who owns the Orlando law firm that employs former governor Charlie Crist (D), has financed most of the pro-medical marijuana side’s $3.1 million campaign.

Polls show the medical marijuana initiative, which qualified for the ballot in January, passing by a wide margin. Already, 18 states and the District of Columbia allow the use of marijuana for medicinal purposes.

Adelson, the chief executive of Las Vegas Sands Corp., spent an estimated $150 million on federal races in 2012 alone. He’s also spent more than $750,000 to support the Florida GOP over the past two elections, according to campaign records.

And he’s always been a big backer of Republican governors; this year, no one needs his largesse more than Pennsylvania Gov. Tom Corbett (R), who faces a 20-point deficit in his bid for a second term.

Earlier this year, Adelson gave $1 million to the Republican Governors Association, which in turn routed the money to a Pennsylvania PAC set up to aid Corbett’s reelection bid.

But the money left Pennsylvania just as quickly as it arrived after officials realized the state law bans donations from Pennsylvania casino owners, according to a report Tuesday by the Philadelphia Daily News. Adelson and his wife, Miriam, have personal stakes in the Sands Casino Resort in Bethlehem, Pa.

Corbett, who has raised $15 million in his reelection bid, is considered one of the most vulnerable Republican governors of this election cycle, trailing 20 points behind millionaire Democrat Tom Wolf in a Quinnipiac University poll last week.