TALLAHASSEE - Las Vegas billionaire casino mogul Sheldon Adelson is opening up his checkbook again to help defeat a medical marijuana proposal.

Campaign finance records filed Friday show Adelson recently donated

$1 million to the political committee that is trying to defeat Amendment 2. Two years ago, Adelson donated $5.5 million to help defeat a similar amendment.

If approved by Florida voters, Amendment 2 would allow the medical use of marijuana.

Amendment backers fell just shy of having medical marijuana approved by voters in 2014. The state requires 60 percent approval for constitutional amendments, and the ballot question was supported by 57.6 percent of voters.

Adelson is a high-profile Republican donor and CEO of Las Vegas Sands Corp. Adelson's wife is a physician who helped found drug-abuse treatment centers.