Has Sheldon Adelson already placed his 2016 bet?

Las Vegas Sands Corp. Chairman and CEO Sheldon Adelson speaks at the Global Gaming Expo (G2E) 2014 at the Venetian Las Vegas on October 1, 2014 in Las Vegas, Nevada.

Ethan Miller, Getty Images

Ahead of a Las Vegas summit gathering together Republican presidential hopefuls for meetings with mega-donor Sheldon Adelson, a new report is out about the casino magnate's purported favorite to win 2016: Florida Sen. Marco Rubio.

Rubio, who recently announced his presidential candidacy, is coming out ahead in what some have dubbed the "Sheldon primary," according to Politico. The news outlet cites sources close to Adelson, who say that the 81-year-old billionaire likes Rubio's strong defense stance, and especially his unflagging support for Israel. The Republican Jewish Coalition, of which Adelson is a board member, is hosting its spring meeting in Nevada this weekend.

The Las Vegas mogul reportedly called Rubio "the future of the Republican party," and added that the young Florida senator's Cuban heritage would widen the draw of a party notoriously comprised of older, white males.

Garnering the support of the 18th richest man in the world could translate into a huge financial boost for Rubio. Adelson's influence in national politics stems from his history of enormous financial donations to Republican Senate and presidential candidates, as well as indirectly via political action committee funding.

Adelson personally spent at least $92 million in the 2012 presidential election cycle, splitting the majority of those funds between first Republican candidates Newt Gingrich, then eventual GOP nominee Mitt Romney.

Adelson's backing kept Gingrich in the race long after other donors gave up on the former House Speaker. But when it comes to picking election winners, the casino mogul has a history of failed gambles.

In total, over 2012 and 2014, 18 of the 36 candidates that the Adelsons funded won their elections, according to a Bloomberg Politics report.

The Adelsons also poured $23 million into conservative super PAC American Crossroads, which supported a number of candidates over the 2012 election cycle. But according to the Sunlight Foundation, just 1.29 percent of the money American Crossroads spent went toward winning races in the 2012 elections. Crossroads, run by former Bush advisor Karl Rove, spent over $104 million in the last election cycle.