Omar's views on Israel were thrust into the center of controversy for the second time in recent weeks on Sunday after she posted a series of critical tweets about pro-Israel lobbying efforts. When Batya Ungar-Sargon of the Forward, a Jewish publication, asked Omar what source of money she was referring to, Omar responded, "AIPAC", meaning the influential pro-Israel lobbying group.
House Speaker Nancy Pelosi leads a group of top Democrats calling on Omar to apologize.
The freshman Democrat came under a massive wave of bipartisan backlash Monday after she implied that pro-Israel lobbyist groups, such as the American Israel Public Affairs Committee, were using campaign contributions to influence US lawmakers.
Omar's mea culpa followed House Speaker Nancy Pelosi's call that the freshman Democrat immediately apologize for the tweets.
Democratic lawmaker Ilhan Omar apologized on Monday after party leaders condemned her use of "anti-Semitic tropes" in suggesting that US congressional support for Israel is a result of campaign donations.
Rep. Deb Haaland (D., N.M.) struggled to defend her fellow Democratic congresswoman Ilhan Omar (Minn.) Monday from charges of anti-Semitism, ultimately pleading ignorance about her string of controversial tweets.
Ms Omar - who in November became one of the first two Muslim women elected to Congress - has been criticised before for criticisms of Israel.
Some of the most ardent pro-Israel Democratic members of the House condemned the tweets, including House Judiciary Committee Chairman Jerrold Nadler and Florida Representative Ted Deutch. She said the statement came in the context of Israel's treatment of Palestinians in the besieged Gaza Strip.
AIPAC, the American Israel Public Affairs Committee, has formidable financial clout, and it prides itself on its influence in United States politics.
"Congresswoman Omar's statements are deeply hurtful to Jews, including myself", New York Democratic Rep. Max Rose tweeted along with a statement.
Even Chelsea Clinton went after Omar but agreed to meet with her to begin a discussion on why her opinion may be wrong.
There is a reason that Ilhan Omar has resorted to anti-Semitic tropes in the the course of her brief public career so far.
Omar's spokesman did not respond to requests for comment. House Judiciary Chairman Jerrold Nadler of NY condemned Omar's tweets Monday morning.
Omar has yet to delete the offensive tweets. Her words are deeply hurtful and offensive, particularly as they build on a previous comment she made about Jews "hypnotizing" the world in support of Israel - another old trope born of hate-filled texts like the Protocols of the Elders of Zion.
The letter's authors, representatives Josh Gottheimer and Elaine Luria, who are both Jewish, did not mention Omar by name, but their intent was clear.
"I fully expect that when we disagree on the Foreign Affairs Committee, we will debate policy on the merits and never question members' motives or resort to personal attacks", he said.