Omar, one of the first two Muslim women elected to Congress and the first to wear a hijab, has drawn criticism from conservatives for a speech last month in which, they say, she downplayed the 2001 terrorist attacks. She was at the centre of an earlier controversy over tweets and a speech criticising the pro-Israel lobby, AIPAC, that some lawmakers, both Democrats and Republicans, found to be anti-Semitic.
Omar, speaking at an event hosted by the Council on American-Islamic Relations last month, was discussing Islamophobia and the treatment of Muslims after 9/11, when she said, "some people did something" that caused all Muslims "to lose access to our civil liberties."
When the video was surfaced last week, conservatives seized on her vague description of the terrorists as anti-American.
But it was the President's tweet that escalated the controversy and caused Speaker Nancy Pelosi, D, to call for increased security for Omar, her family and her offices.
Pelosi said Trump's tweet was "beneath the dignity of the Oval Office."
But that hasn't stemmed the vitriol directed at Omar.
Even a Trump official mocked the death threats to Omar, which only incited more threats.
As first reported by Mother Jones, Lynne Patton, the highest-ranking black woman in the Trump Administration, who serves as a regional administrator at the Department of Housing and Urban Development, shared on her personal Instagram account an image that read: "Ilhan Omar is crying she's receiving death threats. They're not death threats. Just some people saying something."
One cybersecurity expert took it upon himself to monitor all the threats made against Omar on Twitter. He found hundreds since Sunday.