The change in attitude comes amid early jockeying by a lengthy list of aspiring Republican presidential contenders to win the affections of the billionaire, who is in the beginning stages of assessing the field.

“The bar for support is going to be much higher,” said Andy Abboud, Adelson’s top political adviser and an executive at the Adelson-run Las Vegas Sands Corp. He added, “There’s going to be a lot more scrutiny.”

This strategy would favor more established 2016 hopefuls such as former Florida Gov. Jeb Bush, New Jersey Gov. Chris Christie, Wisconsin Gov. Scott Walker and Ohio Gov. John Kasich. All four will descend this week on Adelson’s luxury hotel in Las Vegas, the Venetian, for an important step in what some are calling the “Sheldon primary.”

More: Billionaire Mogul Sheldon Adelson Looks for Mainstream Republican Who Can Win in 2016