GOP presidential hopefuls John Kasich, Donald Trump and Ted Cruz spoke on March 21 at the AIPAC conference in Washington, D.C. (Peter Stevenson/Reuters)

Ted Cruz spoke Hebrew and invoked the nightmare of Adolf Hitler. John Kasich reminisced about "calling my mother on Christmas night" from the city of Bethlehem.

And Donald Trump, the focus of some worried attention at the Israel lobby's main annual event, said that he'd be joining the family.

"My daughter Ivanka is about to have a beautiful Jewish baby," said the Republican presidential front-runner, one of many ad libs in an unusually scripted speech to the American Israel Public Affairs Committee policy conference in Washington.

The specter of Trump hung over the conference for weeks. Some liberal rabbis openly plotted a walk-out to protest Trump, a daunting task at a venue that could only be entered past metal detectors where security staffers checked photo IDs against badges. When one boycotter ducked out for an MSNBC interview, he found himself struggling to re-enter and talk to Fox News. And when Trump spoke, it was hard to see anything like an organized boycott in the Verizon Center, the city's biggest indoor arena.

Still, some attendees left during the speech to meet and talk at a nearby sports bar; others just grimaced until the Republican front-runner was finished.

"If Trump were elected, I would move to Israel and claim political asylum," said Carla Brewington, a one-time anti-war activist from Pasadena, Calif., who is in her 60s. "I won't boo, but I will sit on my hands, I can’t think of a more bigoted, anti-Semitic, misogynistic SOB."

Anyone not paying attention missed a unique Trump performance. The candidate, who once joked that "you shouldn't be allowed to use a teleprompter" if you sought the White House, hewed closely to a script full of AIPAC-friendly promises. "I didn't come here tonight to pander to you about Israel," he insisted; but Trump pledged to move the American embassy to Jerusalem, to demand that Palestinians stopped glorifying terrorists, and to "dismantle" the Iranian nuclear agreement.

"I've studied this issue in greater detail than almost anybody," Trump said of the agreement. He appeared to be startled by laughter from the audience, stifling it with his go-to filler phrase: "Believe me."

Trump's by-the-book performance stayed largely clear of gaffes, and avoided any mention of Israel's security barrier, something he cites when talking to other audiences about his dream of a Mexican border wall.

"I think he'll try to play it straight," said Rep. Brad Sherman (D-Calif.), a resolute AIPAC ally, who watched Trump quietly from the arena's crowded press boxes.

Trump, whose on-message performance was jarring to a media that had covered so many of his speeches, did not mention some of the issues that had rumbled him before. He did add an extraneous "yay" to a line about Barack Obama's final year in office -- to applause. He did not, as he has in recent interviews, suggest that Israel could operate with less foreign aid, or that as president he would remain "neutral" in peace negotiations.

"The parties must negotiate a resolution themselves," he said diplomatically. "The United States can be useful as a facilitator of negotiations, but no one should be telling Israel it must abide by some agreement made by others thousands of miles away that don't even really know what's happening."

Still, Trump seemed to stumble -- without realizing it -- when he referred to the Palestinian territories as Palestine. "Half the population of Palestine has been taken over by the Palestinian ISIS in Hamas," he said.

That created an opening for Cruz, whose hard-line conservative politics did not make him an easy fit with AIPAC's members. Entering to relatively quiet applause, he glanced at the teleprompters, made no joke, then corrected Trump: "Palestine has not existed since 1948."

"Bingo," said Sherman, the Democratic congressman, still watching from the press boxes.

In his aggressive remarks, Cruz mostly left Trump alone, criticizing his "opponent" without naming him for trying to take a "neutral" approach to Israel but otherwise training his fire on the Obama administration.

"This Iranian nuclear deal is Munich 1938, and we risk again catastrophic consequences," he said, comparing the deal to an agreement with Nazi Germany that preceded World War II. Quoting a Hillary Clinton interview that was briefly infamous in 2014, he said that the Democratic front-runner didn't even understand that Hamas placed rockets in populated areas so that anyone fighting back would risk war crimes.

"She said, 'part of it is that Gaza's pretty small and it's very densely populated,'" Cruz said, to quiet groans.

Like Trump, Cruz pledged to start the process of relocating the U.S. Embassy. Like Trump, who had the advantage of speaking first, Cruz shamed Iran for painting the words "Israel must be wiped off the face of the earth" on missiles "in Hebrew and Farsi."

When possible, Cruz went further than Trump; if the United Nations passed a resolution in favor of Palestinian statehood, Cruz pledged to "fly to New York to personally veto that myself." But while speaking about an FAA blockade on flights to Tel Aviv in 2014, there was modest applause when Cruz said he put a hold on State Department nominees -- and wild applause when he mentioned that former New York City mayor Michael Bloomberg defied the blockade by flying his plane to Israel. Despite describing himself as "one of the leading defenders of Israel in the United States Congress," Cruz had a tough sale.

Kasich had an easier one, with no pyrotechnics or call-outs. While Trump referred to his "many awards" from Israel and Cruz cited three years of work in the Senate, Kasich reminisced about the early days of AIPAC -- "you could fit everyone in a hotel ballroom" -- and the fight to free Natan Sharansky from a Russian prison.

"I remain unwavering in my support for the Jewish state and the partnership with Israel," he said. "When Prime Minister Netanyahu spoke to Congress, I flew out to Washington and stood on the floor of the House of Representatives."

One year earlier, the White House's snub of Netanyahu's speech against the Iran negotiations had been the talk of the AIPAC conference. This time, with every remaining Republican presidential candidate alienating the party's foreign policy establishment in some way, the stakes seemed higher, the argument deeper. It was left to House Speaker Paul Ryan to give a lecture on the history of "isolationism," criticizing unnamed politicians who thought America would be safe if it withdrew from the world.

In its way, AIPAC concurred with Ryan. Before any of the candidates spoke, IsraAid's Yotam Polizer talked about the work his group and Israel itself had done to care for refugees from Syria's civil war.

"The people they trusted the least, we protect them, feed them, clothe them," said Polizer.

Moments later, the stage was given over to three Republican candidates who, with varying degrees of vehemence, had opposed the resettlement of those refugees in the United States.