The well-informed, Jewish audience meant that candidates had to bring their A-game on foreign policy and were expected to speak to their pro-Israel stances. The forum also took place the day after the devastating mass shooting in San Bernardino, California, which cast a clear shadow across the event.
Kentucky Sen. Rand Paul was unable to make his afternoon speaking time due to votes in the Senate.
Donald Trump commanded the biggest crowd of the day, but it was clear he knew the audience wasn't seriously considering his candidacy and spent most of his speech making jokes about his familiarity with the room.
"I know everybody in this audience," he joked at one point after recognizing an associate in the front row.
He also cracked about being in a room full of negotiators like himself multiple times during his remarks.
But he also drew boos from the audience when he refused to take a position on whether Jerusalem should be recognized as the capital of Israel.
"You're not going to support me even though I'm going to be the best thing that ever happened to Israel," Trump had said earlier. "And I know why you're not going to support me, it's because I don't want your money."
Trump's lack of specifics but continued success riled one of his opponents, South Carolina Sen. Lindsey Graham, who went off script and used his remarks to implore the audience to stop supporting the business mogul.
"I think Donald Trump is destroying the Republican Party," Graham said. "ISIL loves Donald Trump because he is giving them an opportunity to bring people their way," Graham told reporters after his speech.
It's still Rubio vs. Cruz
The audience's clear favorites of the day included Sens. Ted Cruz and Marco Rubio, two senators with demonstrably pro-Israel track records. The two young, Cuban-American senators are also rising to neck-and-neck in the polls behind front-runner Trump.
On the issue of the civil war in Syria, Cruz and Rubio took different approaches to whether Syrian President Bashar Assad should be removed from power. Cruz, speaking first in the day, warned against U.S.-spurred regime change and spoke out against the Obama administration seeking to remove Assad.
"Toppling a government and allowing radical Islamic terrorists to take over a nation is not benefiting our national security. Putting ISIS or Al Qaeda or the Muslim Brotherhood in charge of yet another state in the Middle East is not benefiting our national security," Cruz said.
Rubio, taking the same stage about a half hour later, had harsh words for that perspective, saying leaving Assad in place creates the conditions for "the next ISIS."
"This simplistic notion that, 'Leave Assad there because he's a brutal killer but he's not as bad as what's going to follow him,' is a fundamental and simplistic and dangerous misunderstanding of the reality of the region," Rubio said in a response to a question about Syria.
The two candidates aren't just duking it out for voters -- they are also making a play to appeal to powerful donors, many of whom pay close attention to the RJC forum. Sheldon Adelson, the billionaire casino mogul and GOP mega-donor, wasn't in attendance on Thursday, but the influential Jewish Republican is deciding whether to use his considerable wealth to support Rubio or Cruz.
Hamas or hummus?
Ben Carson showed his lack of foreign policy experience in precisely the speech experts said he needed to stave off criticisms about his weak spot.
The retired pediatric neurosurgeon delivered an uncharacteristic written address, he said in order to make sure he made all the points he wanted to. But the wooden speech that was heavy on Israeli history and statistics failed to strike a chord with the audience.
He also showed his lack of fluency in the topic as he several times throughout the speech failed to correctly pronounce the name of the Palestinian group Hamas, at one point sounding closer to "hummus."
Carson also was one of the few candidates who didn't take questions.
"(Carson) missed a big opportunity," said RJC board member Ari Fleischer. "He didn't advance his goal of showing any foreign policy. ... I admire him for trying and putting together probably one of the most meaty, substantive speeches you will hear, and what he had to say is very pro-Israel and very good to listen to. It just doesn't work."
There was one issue that all candidates had to weigh in on -- and if they didn't put it in their speech, they were asked about it in Q&A: Jerusalem.
While Israel considers Jerusalem to be its capital, the world community has not recognized it as such while the Israeli-Palestinian conflict continues to dispute the territory. Congress has passed legislation to move the U.S. embassy from Tel Aviv to Jerusalem, but the past three presidents have all periodically issued waivers and maintained the status quo.
On Thursday, all the candidates declared their support for moving the embassy and recognizing Jerusalem as the capital.
Trump was booed when he ducked the question after not mentioning it in his speech.
"I want to wait until I meet with Bibi," Trump said, referring to his upcoming trip to Israel to meet with Prime Minister Benjamin Netanyahu.
As the crowd booed him, he downplayed their reaction, telling the audience to "relax."
"You're going to like me very much," he said. "It's going to be fine."
Jeb still has fans
Former Florida Gov. Jeb Bush has seen his poll numbers drop sharply over the past several months, but he found a warm reception at the RJC forum, where he still has many important boosters.
Bush took the stage to a standing ovation and cheering crowd, and the good will continued throughout his speech.
He won applause when he promised to "whup" Clinton
if he won the nomination, and got plenty of love for his family, as well.
He name-dropped his brother, former President George W. Bush, who got applause from the crowd. "The person I rely on the most as it relates to U.S.-Israeli policy is my brother," he said, to loud cheering. "I've got a damn good brother."
Jeb was asked about his father and mother, George H.W. and Barbara Bush.
He said the elderly patriarch was not watching "CSI" anymore.
"He's now watching Fox again, trying to figure out Donald Trump, I think. That's his main goal in life," Bush joked as the crowd cheered. "Hard for a guy like that to understand the Trump phenomenon."
The super PAC supporting Bush also held a breakfast on the sidelines of the event.
The discussion at RJC was always going to have a heavy national security focus, but the event taking place a day after the San Bernardino shooting added an extra emphasis.
Many of the candidates addressed the shooting at the beginning of their remarks, though they differed on whether to call it terrorism.
Cruz said while details about the shooting in the wake of the Paris attacks were "still unclear," it raised concerns of "radical Islamic terrorism here at home."
"This horrific murder underscores that we are in a time of war," Cruz said.
New Jersey Gov. Chris Christie took a similar tack. "As a former prosecutor ... I am convinced that was a terrorist attack," he said, later adding: "We need to come to grips with the idea that we are in the midst of the next world war."
Carly Fiorina also used her comments on the shooting to attack Democratic front-runner Hillary Clinton for her tweet on Wednesday as the shooting unfolded calling for gun control measures. "Hillary Clinton was tweeting about gun control while we learned that radicalized Islamic terrorists had been building pipe bombs," Fiorina said.
There was one universal sentiment among the White House hopefuls: They call agreed that Democrats should use the term "radical Islamic terrorism."