(CNN) Democratic Rep. Ilhan Omar of Minnesota defended herself Tuesday afternoon against Republican criticism she has faced over a tweet she wrote that slammed a senior White House adviser as a "white nationalist" Monday on Twitter.

"It is the most bizarre thing," Omar told CNN on Capitol Hill on Tuesday, when asked about the condemnation she's faced since she tweeted that "Stephen Miller is a white nationalist" on Monday. In her tweet, Omar pointed to reporting that Miller has been behind President Donald Trump's hardline immigration policies and convinced the President to drop his nominee to lead US Immigration and Customs Enforcement and go in a "tougher direction."

"You know we are talking about someone who truly believes not a single refugee, not a single immigrant, should set foot on American soil," Omar told CNN Tuesday, referencing Miller. "I am appalled by that. Because unlike him and others, I haven't forgotten my roots. I know what it meant for me to get the opportunity to come to the United States to start anew."

Omar also attacked Trump and Miller for what she saw as forgetting their own roots.

"And many of his family and Trump's family came here to get that opportunity and they forget," Omar said. "They forget that that is how ... how they got the chance to become president or work in the White House. Because they got the chance to come to the United States because their families got a chance to come to the United States. So when you get that opportunity, you do not turn your back on the next person who is seeking that opportunity. And I am here to make sure they never forget."

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