Sheldon Adelson, the billionaire casino executive keeping Newt Gingrich's presidential hopes alive, has relayed assurances to Mitt Romney that he will provide even more generous support to his candidacy if he becomes the Republican nominee, several associates said in interviews here.
The signals from Mr. Adelson, whose politics are shaped in large part by his support for Israel, reflect what the associates said was his deep investment in defeating President Obama and his willingness to play a more prominent role in the Republican Party and conservative causes.
The assurances have been conveyed in response to a highly delicate campaign by Mr. Romney and his top Jewish financial supporters to dissuade Mr. Adelson from adding to the $10 million that he and his wife have given to a pro-Gingrich "super PAC," Winning Our Future, that has been tearing into Mr. Romney through television advertising.
Several people who have spoken with Mr. Adelson over the past two weeks said he would most likely continue to help the group as long as Mr. Gingrich remained in the race. But, they said, he is concerned that additional deep-pocketed donors have not joined him. And, they said, his affection for and loyalty to Mr. Gingrich, who met with him here on Friday, have not blinded him to the reality that the nominating contest is tilting in Mr. Romney's favor.
"Sheldon is committed to keeping him in the race as long as he wants to stay in," said Fred Zeidman, a top fund-raiser for Mr. Romney and a longtime friend of Mr. Adelson. "But any time that Newt decides to get out of the race, he would devote his energy and money to the overriding issue, which is beating Barack Obama."
Underscoring Mr. Adelson's devotion to that larger cause, he was among the conservative political financiers on hand last weekend for the twice-yearly gathering of the billionaire industrialists Charles and David Koch near Palm Springs, Calif., where the Kochs and their like-minded colleagues discussed their efforts to ensure Mr. Obama's defeat.
Mr. Adelson, who has long been a behind-the-scenes financier to Republican candidates, is said to be comfortable with a more visible role in the 2012 election. His decision to back the pro-Gingrich group has significantly raised his profile, but friends say he does not want his aid to Mr. Gingrich to be interpreted as anti-Romney.
The Winning Our Future super PAC has mostly run vitriolic television commercials questioning Mr. Romney's character.
"He saw a friend who needed and wanted help," said an associate who talks to Mr. Adelson regularly, speaking on the condition of anonymity to avoid upsetting him. "I don't think it's likely that he's going to fund Newt's death march to Tampa," the site of the Republican National Convention, "but if there is a realistic perception that he can help make his candidacy viable, he will."
Mr. Adelson declined to be interviewed.
His role is especially pronounced in Las Vegas, where his opulent and highly successful Venetian and Palazzo casinos dot the busy skyline.
His connection with Mr. Gingrich goes back years, built on a shared passion for protecting Israel. But associates of Mr. Adelson said that he was concerned about the Obama agenda more broadly and that his support for Mr. Gingrich's candidacy was rooted in a belief that his lofty ideas and forceful approach were right for the challenging times.
Mr. Gingrich, whose campaign treasury is severely depleted, is being advised by his inner circle to spend the weeks leading up to Super Tuesday on March 6 resting up, getting Mr. Romney's attacks out of his head and recalibrating his campaign message to highlight his positive ideas.
But his aides acknowledge that Mr. Adelson's support will be critical to his ability to seriously challenge Mr. Romney, who appeared to be in a strong position for contests in several states this month.
Mr. Gingrich and Mr. Adelson met on Friday afternoon in the Bellini Ballroom of the Venetian Hotel as part of a "Friends of Newt" meeting. Mr. Gingrich and his wife, Callista, stayed four nights at the hotel, which Mr. Adelson owns, but aides said the two men had met only once among a small group of donors and had not discussed the super PAC.
In a brief interview after the meeting, Mr. Gingrich said Mr. Adelson had been vital in giving Winning Our Future the wherewithal to counter the pro-Romney super PAC, Restore Our Future, which had relentlessly attacked him in Iowa.
"He's been a partial match for the Romney super PAC," Mr. Gingrich said. "That's important because, otherwise, the Romney super PAC would have driven us off the field."
When asked if his candidacy could proceed without additional support from Mr. Adelson, Mr. Gingrich did not answer, crossing beneath the bright fresco ceilings into the private dining room of Postrio, a Wolfgang Puck restaurant, where a small group of donors and friends awaited, along with servers pouring red wine.
Fully cognizant that Mr. Adelson is an important factor in determining when Mr. Romney can turn his focus away from Mr. Gingrich and more fully toward Mr. Obama, Mr. Romney and his top financial advisers have been pursuing a careful strategy of outreach to Mr. Adelson.
The effort included a telephone conversation, initiated by Mr. Romney, about two weeks ago, according to three people who were briefed about it and who would discuss it only on the condition of anonymity. They described it as cordial, with Mr. Adelson even sharing some advice about his campaign message.
It was the first time the two men had spoken to each other in about four months. Mr. Romney's campaign had no formal comment, though a senior aide said they shared a "mutual respect for each other."
There are significant links between the Romney campaign and Mr. Adelson, particularly through several top-level donors who raise money for Mr. Romney and sit with Mr. Adelson on the board of the Republican Jewish Coalition, created in 1985 as a way to foster closer ties between the American Jewish community and Republican leaders.
The Romney donors have sought to convey a carefully balanced message to Mr. Adelson, people aware of the discussions said. They warned that continued support for Mr. Gingrich could help Mr. Obama by leaving Republicans wounded and divided but made it clear that Mr. Romney would welcome Mr. Adelson's backing. They also avoided angering Mr. Adelson in a way that might lead him to give more money to Mr. Gingrich out of pique. He is cantankerous, his friends say, and inclined to make his own decisions without relying on conventional wisdom or guidance from political advisers.
Those who are said to have reached out are also described by fellow Republican financiers as being as loyal to Mr. Adelson as they are to Mr. Romney (if not in some cases even more so).
People involved in some of the discussions said Mr. Adelson generally expressed his affection for Mr. Gingrich in explaining his support. But it has been in some of those interactions that Mr. Adelson has made it clear that he will be generous to the broad presidential effort in the fall if Mr. Romney is the nominee. Associates say the message has been conveyed that for a man of Mr. Adelson's wealth, $10 million is a relative pittance and that he is willing to budget much more.
Four years ago, Mr. Adelson supported Rudolph W. Giuliani's presidential bid, but he and Mr. Romney have been friendly for years. Mr. Romney showed up here at Mr. Adelson's side in one of his first 2011 campaign appearances, during a gathering of the Republican Jewish Coalition.
A friend of Mr. Romney's, speaking on the condition of anonymity, said Mr. Romney did not begrudge Mr. Adelson's initial $5 million donation to the pro-Gingrich group, given Mr. Adelson's known loyalty. But Mr. Romney was said to have been deeply stung by a second $5 million donation, from Mr. Adelson's wife, Miriam. And the group's harsh attacks against Mr. Romney were said to have upset Mr. Romney's wife, Ann, though his aides said she was inured to them.
Yet for all of the tension, people close to Mr. Adelson predicted that all would be forgotten if Mr. Romney was the nominee, given that, in the words of one close associate, "he will do whatever it takes to beat Obama in the fall."