Khizr Khan, the father of a Muslim Army captain who was killed in Iraq, said his emotional speech about his son at the Democratic National Convention this week was only part of his message.

Khan addressed Republican nominee Donald Trump directly in his speech, asking if he’d read the U.S. Constitution and telling him, forcefully, “You have sacrificed nothing and no one.” In an interview with MSNBC on Friday, Khan implored Republican leaders to “repudiate Trump,” specifically addressing Senate Majority Leader Mitch McConnell and House Speaker Paul Ryan.

“Isn’t this time to repudiate Trump—what he has said, what he has threatened to do?” Khan said. “This is a moral imperative for both leaders to say to him that, ‘Enough. You are about to sink the ship of the patriot Republicans. Republicans are as patriotic as Democrats are. They are half of the goodness of this beautiful country, half of this political process that the rest of the world watches enviously, learns from it.”

Both McConnell and Ryan have endorsed Trump for president, but have also condemned some of his statements. Ryan called Trump’s criticism of a judge the “textbook definition of a racist comment.” McConnell said Trump should stop attacking minority groups.

“They have disagreed with his practices, his threats to minorities, disrespect to the legal system, legal institutions,” Khan said. “I will continue to ask this question: ‘If your candidate wins and he governs the way he has campaigned, my country, this country will have constitutional crises like never before in the history of this country.’”

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Write to Katie Reilly at Katie.Reilly@time.com.