A partisan wedge dangled Monday over the yearly American Israel Public Affairs Committee Policy Conference — and the overarching U.S.-Israel relationship — as Republicans sought to take political advantage of the close ties between President Trump and Israeli Prime Minister Benjamin Netanyahu and Democrats sought to deflect weeks of controversy over alleged anti-Semitism in their ranks.

This year’s AIPAC conference, attended by more than 18,000 politically active Jewish Americans and other supporters of close U.S.-Israel ties, came as Trump and Netanyahu met in the Oval Office hours after a rocket attack originating from the Gaza Strip focused new attention on Israel’s security and its conflict with Palestinians.

But inside the labyrinthine Washington Convention Center, much of the discussion surrounded whether America’s traditionally bipartisan support for Israel was fraying, with some Democrats openly critical of Netanyahu’s government and one freshman lawmaker, Rep. Ilhan Omar (D-Minn.), under scrutiny for making several comments that implicated anti-Semitic stereotypes.

Speaking Monday morning to thousands of AIPAC attendees, Vice President Pence took dead aim at Democratic critics of the Israel relationship and called for Omar to be removed from the House Foreign Affairs Committee — a direct partisan rebuke delivered at a forum that publicly aspires to be assiduously bipartisan.

While Pence did not mention Omar by name, he described comments that prompted the charges of anti-Semitism — such as tweets, since deleted, that accused Israel of having “hypnotized the world” and suggested that its American supporters were motivated primarily by campaign contributions.

Earlier this month, the House passed an anti-hate resolution after Omar suggested that support for Israel could amount to “allegiance to a foreign country.”

“Anti-Semitism has no place in the Congress of the United States of America,” Pence said, putting the AIPAC crowd on its feet. “And anyone who slanders those who support this historic alliance between the United States and Israel should never have a seat on the Foreign Affairs Committee of the House of Representatives.”

Other Republicans appearing at the conference also lambasted those questioning America’s close ties to Israel as a policy matter. Said House Majority Leader Kevin McCarthy (R-Calif.), “I’d be lying to you if I said that it’s bipartisan in this Congress,” adding that he was “embarrassed” when Democrats moved to broaden a resolution responding to Omar to condemn other forms of hatred besides anti-Semitism. And Rep. Michael McCaul (R-Tex.), the top Republican on the House Foreign Affairs Committee, saidhe was “deeply disturbed by some in the Congress who are threatening this alliance.”

“I don’t think I’ve seen this in the 15 years I’ve been in the Congress, and I don’t have any tolerance for that,” he said.

But key Democrats struck back — from the conference’s main stage, in dozens of smaller sessions and in scores of private receptions and individual conversations — to make clear that they would stand athwart any attempt inside their party to question support for Israel and speak out against any instance of anti-Semitism.

In an address closing Monday’s plenary session, Senate Minority Leader Charles E. Schumer (D-N.Y.) — the nation’s highest-ranking Jewish elected leader — responded indirectly to Omar by defending the patriotism of Israel supporters. He also raised similarly troubling comments from Trump and McCarthy and accused Republicans of playing politics with the issue.

“Let me tell you, if you only care about anti-Semitism coming from your political opponents,” he said, “you are not fully committed to fighting anti-Semitism.”

Speaking on a panel of congressional freshmen, Rep. Max Rose (D-N.Y.) was pressed on the outsize media attention that Omar and her fellow corps of left-wing Democrats have attracted. Rose lamented he didn’t have the social-media following of Omar or colleagues such as Rep. Alexandria Ocasio-Cortez (D-N.Y.) and said rebutting their views on Israel would be a “long game.”

“You should feel hope that irrespective of which party’s in power, the relationship between the United States and Israel is going to be rock solid,” he said. “So long as I’m in Congress, this is a matter of ‘over my dead body,’ all right? We’re going to keep things just the way they are.”

On Sunday evening, House Majority Leader Steny H. Hoyer (D-Md.) offered a sharp defense of the traditional bipartisan pro-Israel consensus — and offered his own thinly veiled rebuke of Omar’s comments suggesting U.S. supporters of Israel could be accused of having competing loyalties.

“Accuse me,” Hoyer said repeatedly, before adding a swipe at the attention garnered by Omar, Ocasio-Cortez and Rep. Rashida Tlaib (D-Mich.) — a Palestinian American freshman who is critical of the Israeli government: “By the way, there are 62 freshmen Democrats. You hear me? Sixty-two, not three.”

Hoyer clarified that comment Monday, explaining that he was “lamenting that the media does not appear to be paying enough attention to other excellent new Members who are also bringing important new energy and diverse perspectives” to Congress.

To the thousands of conference delegates, the internal Democratic clash was a front-burner issue — thanks not only to the turmoil over Omar’s comments but a seeming erosion of enthusiasm for Israel among the declared 2020 presidential candidates. Pence, for instance, blasted Democratic presidential candidates for “boycotting” the AIPAC conference.

While some left-wing groups encouraged candidates not to attend in protest of AIPAC’s support of the current right-wing Israeli government, presidential candidates typically are not invited to speak in nonelection years, according to an AIPAC official. Still, several campaigns confirmed that they would not attend, and Sen. Bernie Sanders (I-Vt.) said last week that his decision was rooted in politics.

“What was once a Mom-and-apple-pie issue that united everyone is now another item on the long laundry list of things that people have differing political outlooks on,” said Jeremy Ben-Ami, president of J Street, a pro-Israel group critical of AIPAC’s close ties to the political right. “Trump and Netanyahu are pursuing a set of policies that are essentially anathema to the overwhelming majority of Jewish Americans.”

That partisan backdrop prompted 34-year-old Shira Kessock of Oceanside, N.Y., to press Rep. Josh Gottheimer (D-N.J.) to respond to what she saw as a rising tide of extremism in the Democratic ranks — comparing it to the crisis over anti-Semitism that rocked the British Labour Party.

“I don’t want to see Democrats driven away from talking about their Israel bona fides. I want them part of this, and it scares me,” Kessock, who identifies as a conservative, said in an interview. The Democratic critics of Israel, she added, “have big, big voices, and it’s drowning out the centrists. You can’t let your fringe element become your party and start holding the mic. We don’t want a Jeremy Corbyn situation here in the U.S.,” referring to the leader of Britain’s Labour Party.

But Ken Steinberg, another delegate attending the same forum, said his concern about eroding bipartisanship was rooted elsewhere — specifically, with Trump.

“Whatever fear and hatred is out there, he’s lit a fire under all of it,” said Steinberg, chairman of the Memphis Jewish Federation. “Things like Omar and people like that — her getting elected is a function of the Trump presidency and his ranting and raving and tweeting.”

Pressed on the seeming erosion of the pro-Israel consensus, Gottheimer gave a frank answer: “You’ve put your figure on an issue we’re all talking about and trying to grapple with,” he told another attendee. “I wish I had a one-word answer for you. I don’t.”

Gottheimer, who pushed for a more forceful response to Omar’s most recent comments, said “both sides” are using Israel and the threat of anti-Semitism as a political wedge and said both parties needed to respond: “We can’t have this rhetoric. We can’t use these tropes. We can’t make these claims,” he said. “Any little comment is unacceptable and has to be addressed immediately.”

While several conference attendees said in interviews that they felt reassured by Democrats who spoke Sunday and Monday, Trump remains overwhelmingly popular inside the AIPAC ranks after following through on several of the group’s key policy objectives. Trump moved the U.S. Embassy to Jerusalem and withdrew from the 2015 nuclear deal with Iran, and on Monday he formalized another Israeli objective other presidents have long resisted — formally recognizing permanent Israeli control over the Golan Heights, territory it seized from Syria during the 1967 Six Day War but whose status has been internationally disputed since.

In the Oval Office on Monday, Netanyahu said, “I’ve met many friends of Israel in this office, but . . . we have never had a greater friend than President Trump.” When Pence and AIPAC President Mort Fridman separately hailed the recognition of Israeli sovereignty over the Golan on Monday, the crowd responded with raucous applause.

That response, in part, has Republicans hoping for a better showing among Jewish voters who have long favored Democrats overwhelmingly.

Barbara Cohen, a Trump supporter from Florida, said after Pence’s speech that she viewed the Democrats’ defensiveness on Israel as “emblematic of a shift” taking place inside the party.

“They still say the word bipartisan, but I see the oncoming generation shifting away from that,” she said. “I don’t know if the Jewish vote will totally swing the other way, but it will hurt them — it will hurt them with fundraising, and it will hurt them with votes.”