Las Vegas Sands Chairman and CEO Sheldon Adelson speaks during a luncheon at Gaming Expo Asia in Macau June 8, 2011. REUTERS

Newt Gingrich's resurgent presidential campaign owes much to the billionaire casino magnate Sheldon Adelson and his wife Miriam, who have in the last few weeks given a combined $10 million to the pro-Gingrich Super PAC Winning Our Future.

With two separate infusions of $5 million, the Adelsons have played an outsized role in shaping the course of the Republican presidential race so far, raising questions about who Sheldon Adelson is and why he is motivated to back Gingrich so aggressively.

While those contributions have just now put him in the glare of campaign coverage, Adelson has supported the former speaker for years. The Center for Responsive Politics found that he donated $7.7 million between 2006 and 2010 to American Solutions for Winning the Future, a political committee that was crucial in laying the foundation for Gingrich's current campaign. Politico reported in December that Adelson had discussed his plans to donate $20 million to the campaign.

My motivation for helping Newt is simple and should not be mistaken for anything other than the fact that my wife Miriam and I hold our friendship with him very dear and are doing what we can as private citizens to support his candidacy, Adelson said in a statement to the Washington Post.

While the two men solidified their relationship when Adelson sought then-Speaker Gingrich's help in combatting labor unions who were organizing around the Venetian, a lavish Las Vegas resort-hotel Adelson opened in 1999, the Washington Post notes that Adelson traces their relationship to a previous meeting in the Capitol Rotunda. Adelson was there to support legislation that would move the American Embassy in Israel from Tel Aviv to Jerusalem, something Gingrich has vowed to accomplish with an executive order on his first day as president.

Sheldon has always loved Newt, Fred Zeidman, a friend of Adelson, told the Daily Beast. He stuck with him through all of this. He stuck with him when he stumbled. Newt, I think, is very reflective of Sheldon's mindset. Particularly with Israel.

Numerous media accounts have detailed how Adelson has used his immense wealth to win substantial influence in Israel. A contributor to organizations that have included the Republican Jewish Coalition and the American Israeli Public Affairs Committee, Adelson also launched a free daily Israeli newspaper, Israel HaYom, that is widely viewed as backing right-wing Prime Minister Benjamin Netanyahu. Commentators have dubbed the newspaper Bibi-ton, or Bibi Sheet, an allusion to Netanyahu's nickname.

The Adelson phenomenon is not healthy for Israeli society and Israeli democracy, the columnist Nahum Barnea said in an interview with the magazine Firma, adding that That newspaper is in its contents so devoted, loyal, vested in personal interests for Netanyahu.

A New Yorker profile of Adelson described him as fiercely opposed to a two-state solution for Israel and Palestine and detailed his animosity for former Israeli Prime Minister Ehud Olmert, who supported a two-state solution and opened peace talks with Palestinian Authority President Mahmoud Abbas. Such views seem to align Adelson with Gingrich, who has also taken a hawkish stance on Israel.

When Gingrich ignited controversy for suggesting that the Palestinians are an invented people, Adelson defended him. Read the history of those who call themselves Palestinians, and you will hear why Gingrich said recently that the Palestinians are an invented people, Adelson told young American Jews visiting Israel under the auspices of Taglit Birthright, an organization to which Adelson has contributed millions.

Gingrich and Adelson also have common purpose in their opposition to organized labor. The New Yorker profile cites testimony from Shelley Berkley, a Democratic congresswoman from Nevada who was Adelson's vice-president of legal and governmental affairs when he was fighting organized labor over the Venetian hotel. Berkley says Adelson told her that Democrats were with the union and he wanted to break the back of the union, consequently he had to break the back of the Democrats.

Berkley later wrote in a letter to the Las Vegas Review-Journal that Adelson turned against her when she expressed sympathy for the workers. She said that Adelson had offered to fund her congressional campaign if she switched from the Democratic to the Republican ticket.

I have unique personal knowledge, Berkley wrote, of how Mr. Adelson seeks to dominate politics and public policy through the raw power of money.