Sen. Marco Rubio has become the latest Republican to rebuff Donald Trump over comments about Capt. Humayun Khan’s parents but, like others, he did not withdraw his support for the GOP presidential nominee.

“I think his parents are heroes and they have a First Amendment right to speak out on their politics, as all Americans do. Their son died for the Constitution, and I honor that,” the Florida Republican, a former Trump rival, said Monday in Clearwater, Florida.

Khizr Khan, whose son Humayun was killed by a car bomb in 2004 while serving in Iraq, spoke at the Democratic National Convention in Philadelphia last week, where he criticized Trump for his invective against Muslims and asked if he had ever read the U.S. Constitution.

In what’s become a widely ridiculed statement, Trump said over the weekend, “Mr. Khan who has never met me, has no right to stand in front of millions of people and claim I have never read the Constitution, (which is false) and say many other inaccurate things.”

The real estate mogul also questioned why Khan’s wife, Ghazala Khan, remained silent on stage in Philadelphia, suggesting she wasn’t allowed to speak because of her Muslim faith.