Republican Jewish Coalition board member Sheldon Adelson applauds during a March roundtable discussion on Capitol Hill with his wife Miriam Adelson (center) and Marion Wiesel (left). (Win Mcnamee/Getty Images)

Tension between the Obama administration and Israeli Prime Minister Benjamin Netanyahu has fueled a fundraising bonanza for a conservative advocacy group that serves as an influential hub of wealthy Jewish donors on the right.

The Republican Jewish Coalition — whose board includes casino magnate Sheldon Adelson and other GOP mega-donors — has brought in scores of new contributors alarmed by the open sparring between President Obama and Netanyahu over how to curb Iran’s nuclear capabilities, said Matthew Brooks, the RJC’s executive director.

“Our national fundraising has been exploding as a result of this,” Brooks said. “There are a lot of folks who are deeply troubled by the actions of this administration and the undermining of the relationship with Israel and with Prime Minister Netanyahu, and as a result, I think, they are engaged and energized in a way I have never seen before.”

The White House declined to comment. Obama has urged Republicans not to “politicize” the U.S.-Israeli relationship, stressing the “unbreakable bond” between the two countries.

Sheldon Adelson, a Republican Jewish Coalition board member, and his wife Miriam attend Israeli Prime Minister Benjamin Netanyahu’s speech before a joint meeting of Congress on March 3. (Chip Somodevilla/Getty Images)

Brooks would not disclose how much the group has raised but said the RJC is on track to bring in record sums. The organization plans to finance its largest voter outreach ever in the 2016 elections.

In the 2012 cycle, the organization brought in $13 million and spent at least $4.5 million on ads opposing Obama’s reelection, according to tax records and campaign finance filings. An affiliated super PAC plowed an additional $1.8 million into anti-Obama spots, funded entirely by Adelson and his wife, Miriam.

Most of the RJC’s political spending has been done through its nonprofit arm, allowing it to keep its backers’ names secret. But the coalition’s board of directors includes many of the wealthiest donors on the right, including billionaire hedge-fund executive Paul Singer, home builder Larry Mizel and Mel Sembler, former ambassador to Australia and ­Italy. Adelson — who has an estimated net worth of nearly $30 billion — is a staunch Netanyahu ally and owns a free daily tabloid in Israel.

RJC officials said that the group’s leaders are putting more resources into the organization but that they also have seen an influx of smaller donors who are giving for the first time. Many are attending the RJC’s spring leadership meeting in Las Vegas this week, where former president George W. Bush will be a featured speaker.

The three-day event at the Venetian hotel-casino is set to draw several 2016 presidential contenders and a record 700 attendees, up from 400 last year. All have given at least $1,000 to be part of the RJC’s tiered donor clubs, which go up to $50,000 at the chairman level. The meeting, most of which is closed to the media, kicked off Thursday night with a private dinner at Adelson’s home for the RJC board and top donors. Mitt Romney, the 2012 GOP presidential nominee, will be a featured guest, along with Republican National Committee Chairman Reince Priebus.

House Speaker John A. Boehner is addressing the group at lunch Friday, while Rep. Edward R. Royce and Majority Leader Kevin McCarthy, both of California, will speak at a Shabbat dinner Friday night.

On Saturday, Sen. Ted Cruz of Texas, former Texas governor Rick Perry, Sen. Rob Portman of Ohio and Indiana Gov. Mike Pence are scheduled to address the audience, while Bush will answer questions about the presidency and leadership in an off-the-record session Saturday evening.

Among those attending for the first time will be Lisa Karlovsky, a mother of three who lives in Phoenix. Karlovsky said she and her husband joined the RJC in February after watching the administration’s handling of the nuclear negotiations with Iran.

“We’re making nice with them,” she said. “This is unprecedented and unbelievable. This is the scariest thing that I’ve experienced, ever.”

Brad Rose, a lawyer in Manhattan, said he has increased his annual donation to the group to $50,000, up from the $10,000 he gave when he joined a few years ago. In the past year, he said he has recruited several people to join at top donor levels.

“Where people before were very reluctant to give the organization a fair shake, I find now I’ve been able to provoke interest,” he said. “A lot of it is really motivated by the perception that the Obama administration has been very, very negative in its policies toward the Middle East, and especially with respect to Israel.”

RJC officials said the group’s growing ranks reflect a broader dissatisfaction among American Jews with the Democratic Party. In 2016, the RJC plans a “robust campaign” targeted at Jewish voters, urging them to support the GOP presidential nominee, Brooks said.

The GOP has expanded its share of the national Jewish vote in recent elections, garnering 30 percent of Jewish support in 2012, up from 21 percent in 2008, according to exit polls. But Jewish Americans remain a reliable Democratic constituency, recent surveys show.

A Pew Research Center report released last week, based on data gathered over the past year, found that 61 percent of Jewish Americans identify as Democrats or independents who lean Democratic, compared with 31 percent who identify as Republicans or GOP-leaning.

Democratic Jewish leaders reject the notion that a large swath of the Jewish community is moving to the GOP.

“The data is pretty clear,” said Greg Rosenbaum, chairman of the National Jewish Democratic Council. “The Jewish community still strongly supports Democrats.”

Liberal Jewish activists said the RJC injected partisan politics into the Iranian negotiations, noting that the organization ran full-page newspaper ads touting Netanyahu’s controversial address to Congress last month.

“There has been a tremendous push by RJC and other right-wing groups to try to create” a backlash against the Obama administration, said Hadar Susskind, director of Bend the Arc, a liberal advocacy group focused on domestic issues. “I think there is very little evidence of it [succeeding]. Overall, the people who say that and share those views didn’t vote for Obama and didn’t like him eight years ago.”

Peyton Craighill contributed to this report.