In a statement late Sunday, Omar said many of those threatening her life directly referenced Trump's post.
Whereas Trump's attacks on Omar are merely an attempt to funnel fuel to his base of right-wing conservative voters as he gears up for elections in 2020, the manner in which Omar has been treated by her own party seems to invoke a larger and deep seated story of Islamophobia and anti-Muslim racism that has been an integral feature of America - as we know it - for decades.
A number of prominent Democrats have condemned President Donald Trump for quoting Rep. Ilhan Omar's (D-Minn.) dismissive description of the 9/11 terrorist attacks while at the same time, haven't disavowing the content of their colleague's remarks.
Asked on "Fox News Sunday" whether Trump is anxious he was inciting violence against Muslims or Omar, 37, a Somali-American who immigrated with her family to the U.S. as a teenager after living in a Kenyan refugee camp, Sanders said no.
Soon after Ms Pelosi's statement, the video was no longer a pinned tweet at the top of Mr Trump's Twitter feed, but it had not been deleted.
As the spotlight falls on Somali-American Ilhan Omar, the first African refugee in the U.S. Congress, so are the death threats against her after U.S. President Donald Trump's relentless attacks on her. "We are all Americans".
On Friday, Trump tweeted a video that juxtaposed the snippet - which Omar's fellow Democrats say was taken out of context - with images of the hijacked planes used in the attacks crashing into the World Trade Center's twin towers that once dominated New York's skyline.
But, she added: "The president is absolutely and should be calling out the congresswoman for her not only one-time but history of anti-Semitic comments".
"President Trump must take down his disrespectful and unsafe video", she said, adding that security officials are reviewing Ms Omar's protection and "will continue to monitor and address the threats she faces".
House Speaker Nancy Pelosi said the memories of the September 11, 2001, terrorist attack on NY and Washington are "sacred ground and any discussion of it must be done with reverence".
She is one of the first Muslim women elected to Congress and the first person to wear a hijab in the House chamber.
Omar has faced a slew of attacks and death threats in recent weeks, along with ongoing criticisms since she made scathing comments against Israel, and now with comments she made on the September 11 attacks.
"Violent crimes and other acts of hate by right-wing extremists and white nationalists are on the rise in this country and around the world", she said.
"She is out of control, except for her control of Nancy!" he tweeted.
Mr Trump captioned his tweet with: "WE WILL NEVER FORGET!"
Critics accuse Ms Omar of being flippant in describing the perpetrators of the attacks that killed almost 3,000 people.
Democratic presidential candidate Bernie Sanders noted that then-President George W. Bush, a Republican, went to a mosque after 9/11 to assure Muslim Americans that they are not criminals and terrorists.
Neither Trump's tweet nor the video included Omar's full quote or the context of her comments, which were about Muslims feeling that their civil liberties had eroded after the attacks.
"The bigger question is why aren't Democrats doing the same thing? It's absolutely abhorrent the comments that she continues to make and has made and they look the other way". "It has to stop", she said. But she refused to take back a tweet in which she suggested American supporters of Israel "pledge allegiance" to a foreign country.
"This whole process has really been one of growth for me", she told Colbert. "He's actually speaking out against it", Sanders said on Fox. Nadler appeared on CNN's "State of the Union".