LAS VEGAS — President Trump on Saturday again declared that the United States was “full” and called its asylum system “a scam,” tying his push to close the country’s borders to undocumented immigrants and asylum seekers to an entreaty for Jewish voters to support his re-election campaign.
“Our system’s full; our country’s full,” Mr. Trump said, speaking to an audience that included descendants of Holocaust survivors, Jews in red skullcaps emblazoned with “Trump” in white thread and people carrying Israeli flags. “You can’t come in. Our country is full. What can we do? We can’t handle any more. Our country’s full. You can’t come in, I’m sorry.”
He was met with raucous applause and cheers at the Republican Jewish Coalition’s annual leadership meeting in Las Vegas, underscoring how many conservative Jewish voters, alarmed by rising threats of anti-Semitism and energized by his pro-Israel policies, have embraced a president with a history of trafficking in anti-Semitic tropes — including remarks that he has made before the coalition.
Fresh from a visit on Friday to a California border town, the president doubled down on his attacks on migrants seeking asylum at the border. The administration has recently toughened its policy for accepting asylum seekers, with stories of fleeing violence and corruption no longer meeting the standard for entry.
“The asylum program is a scam,” he said, describing people “who look like they should be fighting for the U.F.C.,” with large muscles and face tattoos. “Some of the roughest people you’ve ever seen.”
Mr. Trump has sought to paint himself as a chief supporter of Israel, trumpeting the fulfillment of his promise to move the American Embassy to Jerusalem and his decision to recognize Israel’s authority over the long-contested Golan Heights. Vice President Mike Pence, in a speech later Saturday, called the president “the greatest friend of the Jewish people ever to sit in the Oval Office.”
Like the lawmakers who spoke before him — Representative Lee Zeldin of New York, one of two Republican Jewish representatives, and Representative Kevin McCarthy of California, the minority leader — the president framed Democrats as unwilling to combat anti-Semitism.
“Republicans believe that we must never ignore the vile poison of anti-Semitism,” Mr. Trump said. He brought the crowd to its feet by introducing Timothy Matson, a police officer wounded during the shooting in October at the Tree of Life synagogue in Pittsburgh.
In condemning anti-Semitism, all three men singled out Representative Ilhan Omar, the freshman Democrat from Minnesota and one of the first two Muslim women elected to Congress, who for weeks has fended off accusations of anti-Semitism over comments critical of Israel.
“Special thanks to Representative Omar of Minnesota,” Mr. Trump said, expressing gratitude to other attendees, including Sheldon G. Adelson, the billionaire casino magnate and prominent Republican donor, and his wife, Miriam. “Oh, I forgot, she doesn’t like Israel. I’m so sorry.”
(Ms. Omar herself was recently the target of death threats. This week, federal agents arrested a New York resident, Patrick W. Carlineo Jr., after he reportedly called her office, described her as “a terrorist” and promised, in an expletive-laden threat, to “put a bullet in her skull.”)
Ms. Omar later responded on Twitter by quoting a prayer of forgiveness: “My Lord, forgive my people for they do not know.”
Mr. Trump also appeared to blur the lines between the American Jews in the audience and Israelis, referring at one point to Prime Minister Benjamin Netanyahu of Israel as “your prime minister” and warning that congressional Democrats “could leave Israel out there all by yourselves.”
At one point, he asked the crowd, “How the hell did you support President Obama? How the hell did you support the Democrats?” Reminded by the audience that members of the Republican Jewish Coalition did not, in fact, support Mr. Obama, he laughed before conceding: “You guys didn’t. That’s right.”
A few protesters were escorted from the arena early on in the speech, chanting “Jews are here to say: Occupation is a plague,” according to IfNotNow, a Jewish organization that issued a statement afterward. Logan Bayroff, a spokesman for J Street, the liberal Jewish organization, said the president’s remarks about immigrants and minorities were “extremely discordant and extremely disgusting to the majority of Jewish people.”
But the crowd of supporters in the ballroom at the Venetian hotel and casino were enthusiastic as the president delivered a cornucopia of boasts, complaints and exaggerations typical of his campaign rallies: efforts to overhaul trade deals with Mexico and China, and his pledge to build a border wall. Cheers of “four more years” rang out after Mr. Trump left.
The president’s claims about the country’s capacity to support more immigrants echoed an argument he made on Friday during his visit to a border town in California, backing down from a threat to close the legal ports of entry between the United States and Mexico.
Allies of the president have argued that he is right to push to overhaul the process, with the surge of families turning themselves in to Border Patrol agents at the ports of entry or in between them.
“What you see happening here is an abuse of asylum laws,” Senator Lindsey Graham, Republican of South Carolina and a close ally of the president’s, said in a brief interview after Mr. Trump’s speech. “If asylum is going to be that everybody who is economically impoverished can come to America, there will be no way we can handle the flow.”
“Bottom line is,” he added, “we accept refugees.”