The well-dressed attendees of this weekend’s spring meeting of the Republican Jewish Coalition stood out at the Venetian hotel and resort in Las Vegas. Few could be spotted wandering the casino floor, let alone indulging in any of the multitude of vices available in Sin City. Most people go to Vegas to let loose. They were there to save the world.

In contrast to the rest of the gaudy hotel – owned by major Republican donor and presidential kingmaker Sheldon Adelson – the main events of the meeting took place in a bland ballroom off in a corner of the hotel.

Attendees flocked in droves to the meeting of the well-funded pro-Israel lobby group, spurred by what they see as the disastrous foreign policy of the Obama administration. In particular, the provisional nuclear framework agreement reached with Iran in March was viewed as “a bad deal” which empowered an Islamic fundamentalist regime bent on destroying Israel and hurting the United States.

As former senator Norm Coleman told reporters: “The threats that those of us in the pro-Israel community see are greater than they’ve ever been before. Iran getting a nuclear weapon is an existential threat to Israel and a threat to all of us.”

Even George W Bush, in a rare appearance behind closed doors, criticized his successor’s foreign policy as too weak on the Islamic State and the nuclear negotiations with Iran, according to reports. (An attendee also confirmed to the Guardian that Bush told donors his brother Jeb’s campaign for the White House might be damaged by their shared last name, acknowledging voters had limited appetite for “dynasties”.)

Organizers boasted that attendance was up 200% over the past two years, reflecting the fact that Jewish support for the GOP is the highest it has been in decades. “Our best recruiting agents have been Barack Obama and Hillary Clinton,” boasted Mark McNulty, a spokesman for the group. But McNulty was only half right: Clinton went almost unmentioned, save for her service in the Obama administration.

Yet for all the disdain expressed toward Obama, the tone was far less partisan than one would expect. Attendees, many of whom started life as Democrats, seemed to mourn what they saw as the leftward drift of the party on foreign policy. Even Ted Cruz took the stage to bemoan that not only were there no longer “Scoop Jackson Democrats” (a reference to the stridently anti-communist Washington senator in the 1960s and 1970s), but there weren’t any Joe Lieberman Democrats either.

Coleman, a former Democrat himself, was more measured than Cruz. He noted: “Only Democrats didn’t show up when [Israeli prime minister] Bibi Netanyahu spoke [to Congress]. It breaks my heart, but I’m putting that at the feet of the president.” Coleman, though, expressed fervently his hope that support for Israel “doesn’t become a partisan issue”. The former Minnesota senator argued that “in order to defeat a bad Iran deal, you’re going to need Democrats”.

But the event wasn’t just an opportunity for attendees to vent about Obama – it was a chance for them try to decide who they wanted to succeed him.

Perry and Cruz spoke to the group in open appearances, while the hawkish South Carolina senator Lindsey Graham, former New York governor George Pataki and Michigan governor Rick Snyder – who emerged as a potential presidential candidate over the weekend – mingled in private along with staff members and major donors.

Attendees also met privately with Bush, House speaker John Boehner and Mitt Romney, whose 2012 presidential campaign was backed by $150m in campaign spending by Adelson, the eighth-richest person on the planet.

“This is a chance for candidates to step out and show the audience what they have,” former Bush press secretary Ari Fleischer told the Guardian. “This is also a sophisticated audience which is following the candidates who aren’t here as they campaign.”

While no clear frontrunner for financial backing emerged from the donor gathering, the names of Bush, Florida senator Marco Rubio and Wisconsin governor Scott Walker surfaced repeatedly as a kind of top tier in conversation with donors.

Not that attendees were terribly concerned about the exact foreign policy positions of the candidates in attendance or their candidates-in-waiting. As Cruz joked: “It’s not complicated for Republican politicians to come to the RJC and say, ‘We should stand with Israel.’ Unless you’re a blithering idiot, that’s what you say when you come here.”

The only leading Republican contender to have vocally strayed from the conservative foreign policy orthodoxy has been Rand Paul, who was a nonentity at the meeting this year.

Since his 2010 election to the Senate, Paul has worked hard to woo pro-Israel donors and voters wary of his father’s isolationist foreign policy, and it seems to have worked; the Kentucky senator was considered just another candidate in the field at this gathering, a major achievement considering the skepticism he had once produced in the pro-Israel community. “His name hasn’t even come up,” Fleischer said.

Amid such ideological homogeneity and a Republican field that former House speaker Newt Gingrich on Sunday said could balloon to 25 candidates, donors have been looking at another standout factor: electability.

Cruz especially tried to sell himself as capable of winning a general election against Clinton, a former secretary of state whom Republicans have already sought to align with “a third Obama term”.

Instead of the social-conservative red meat he often offers larger audiences, Cruz emphasized his bipartisan work on pro-Israel legislation and his fundraising success since announcing his candidacy in March.

If it was all for the benefit of Adelson, there was no white smoke fluttering from the Venetian. The casino mogul, who met privately with candidates at the event and didn’t make a public appearance, still has yet to pick a candidate as he prepares for a court appearance this week.

Then again, he has a big field to choose from.

After all, as Coleman said, Republicans have “a field of thoroughbreds” heading into 2016.

“Last time, we had Mitt Romney and some other guys.”