Mark Kirk isn’t much better than Donald Trump.

In June, Kirk said Trump was “too bigoted and racist” to be president and “does not have the temperament” to serve as an effective commander-in-chief. Just a few weeks ago, amidst the fallout from the Billy Bush tape, he called on Trump to withdraw from the ticket. (Kirk has said that he plans on writing David Petraeus’s name on his ballot for president, for some reason.)

But the main reason Kirk opposes Trump is because he has the most vulnerable seat in the Senate. His opponent, Tammy Duckworth, has done a very good job of lashing him to Trump. The polling suggests that Duckworth, a veteran who lost both legs in the Iraq War, is leading Kirk by a fairly substantial margin.

In a debate on Thursday, Duckworth discussed the importance of service in her family—she was born to a Thai-Chinese mother and a U.S. Marine father whose family has been in the United States since it was a British colony. After Duckworth described herself as a “Daughter of the Revolution,” Kirk replied, “I forgot that your parents came all the way from Thailand to serve George Washington.”

Ironically, given Kirk’s attempts to distance himself from Trump, this is the exact kind of racially charged comment that Trump has made again and again this election. Kirk is arguing that Duckworth’s background and appearance somehow make her less American. Kirk, who has a history of making racially charged statements, has not apologized. Duckworth, meanwhile, has taken the high road—she didn’t respond to Kirk’s dig but tweeted this after the debate: