Washington CNN  — 

Republican Rep. Adam Kinzinger of Illinois on Thursday morning called a chant that broke out at President Donald Trump’s rally the previous night – when the crowd yelled “send her back” as the President targeted Democratic Rep. Ilhan Omar of Minnesota – “ugly” and “wrong” and said it “would send chills down the spines of our Founding Fathers.”

“I deeply disagree with the extreme left & have been disgusted by their tone. I woke up today equally disgusted - chants like ‘send her back’ are ugly, wrong, & would send chills down the spines of our Founding Fathers. This ugliness must end, or we risk our great union,” Kinzinger said in a tweet on Thursday morning.

The crowd broke out with chants of “send her back,” after the President went on the attack during a rally in Greenville, North Carolina, against Omar, the first Somali-American member of Congress, who came to the US as a refugee over two decades ago. Omar also made history alongside Rep. Rashida Tlaib of Michigan at their swearing in as the first two Muslim women to serve in Congress.

Omar responded to the rally last night, saying on Twitter, “I am where I belong, at the people’s house and you’re just gonna have to deal!” Omar’s message appeared next to a picture of her on the House floor with the American flag in the background.

The chant at Trump’s rally comes as the President has repeatedly attacked Omar as well as the three other progressive Democratic congresswomen of color known as “The Squad” using racist language.

Many congressional Republicans rebuked the President over his attacks earlier in the week, but House GOP leaders came to the defense of the President, arguing that his attacks were not racist, while Senate Majority Leader Mitch McConnell said, “the President’s not a racist.”

The House voted on Tuesday to approve a resolution condemning the President’s racist comments directed at the members of Congress.