Democratic presidential nominee Hillary Clinton weighed in on the race for the Illinois Senate seat Tuesday, criticizing Sen. Mark Kirk’s (R-Ill.) remarks on Rep. Tammy Duckworth’s (D-Ill.) heritage in an op-ed published on NBC News’ website.

Clinton’s op-ed, published on Tuesday, is titled “As President, I Will Stand With Asian Americans and Pacific Islanders.” Duckworth, who lost both her legs while serving as a helicopter pilot for the U.S. Army in Iraq, was born in Bangkok, Thailand, to a Thai mother and an American father.

Kirk questioned Duckworth’s family military history and heritage in Thursday night’s debate. Duckworth said her family has served the United States going back to the revolution.

“I forgot your parents came all the way from Thailand to serve George Washington,” Kirk said in response.

Clinton began the op-ed with a reaction to Kirk’s comment.

“When I heard it, I couldn’t believe it,” the op-ed said. “In other words: you can’t have Thai heritage and trace your American roots back to the start of our nation. That’s just plain wrong.”

Clinton’s piece extended beyond a criticism of Kirk’s remarks, describing this election as one filled with racist and insensitive comments targeting the Asian American community. She pointed to a Fox News’ segment about Chinatown that she said perpetuated the “worst racial stereotypes of Asian Americans” and instances in which Donald Trump mocked the accents of Chinese and Indian people in his speeches.

Kirk has lost two critical endorsements after his remarks during last Thursday’s debate. The Human Rights Campaign and Americans for Responsible Solutions, the anti-gun violence PAC founded by former congresswoman Gabrielle Giffords, both revoked endorsements.

The Kirk campaign did not respond to a request for comment on the loss of both endorsements.