With Donald Trump just 103 delegates short of securing the Republican presidential nomination, the top individual donor in the last presidential election cycle is now backing him.

Billionaire casino owner Sheldon Adelson, who publicly endorsed Trump on Friday, has privately informed him of plans to give potentially more than $100 million to groups and super PACs backing Trump, according to the New York Times.

Adelson gave $93 million in 2012 to groups supporting republicans, including Mitt Romney and Newt Gingrich.

Trump is reportedly considering Gingrich, a former speaker of the House of Representatives, to be his running mate.