Casino magnate and Republican megadonor Sheldon Adelson and his wife, Miriam, each gave the legal maximum $2,700 to Texas Sen. Ted Cruz's campaign in November, reports filed late Sunday with the Federal Election Commission showed.

Mr. Adelson, who in 2012 poured more than $100 million into Republican campaigns, has not yet endorsed a candidate in the 2016 cycle. The chairman of Las Vegas Sands Corp. remains the prized catch for GOP candidates, who have spent months courting him. He has reportedly expressed interest in Mr....