The $5 million check that casino mogul Sheldon Adelson wrote to help his friend Newt Gingrich win his party's presidential nomination is expected to be followed by much more support aimed at helping the GOP's eventual winner, including several million dollars for a Karl Rove-created group.

Adelson’s contribution went to “Winning Our Future,” a super PAC that is supporting the former House Speaker for president, say GOP fundraisers familiar with the donation.

But fundraisers close to the billionaire say he will pour at least a few million dollars this year into the super PAC American Crossroads, or its affiliate Crossroads GPS, to help the GOP nominee — whether it is Gingrich or someone else.

Adelson, the CEO of the Las Vegas Sands, has been close to Rove since he was the top political guru to former President George W. Bush. Adelson wrote a seven-figure check in 2010 to the group’s nonprofit arm, Crossroads GPS, say fundraisers with ties to Adelson and Rove. The group is not required to reveal its donors.

Ron Reese, a spokesman for Adelson and his sprawling casino empire, declined to comment. Jonathan Collegio, a spokesman for the two Crossroads groups, said that the GPS arm “does not comment on who does or does not donate to the organization.”

Super PACs can accept unlimited contributions from individuals and corporations and use the funds to support or oppose candidates, but are banned from coordinating with their campaigns.

Just how much more Gingrich’s super PAC receives from Adelson is expected to depend on how the Georgian does in the January 21 South Carolina primary, where polls show he’s lost his earlier lead to Mitt Romney. Adelson has long been a supporter of Gingrich. The two men ...