Senator John McCain
Senator John McCainReuters

Has Donald Trump finally gone too far?

After Khizr Khan told the heart-rending story of his soldier son's death while speaking at the Democratic National Convention, Trump's response was to ridicule the immigrant's origins, asking if his Muslim wife was even allowed to speak.

Khizr had challenged Trump: "Have you ever been to Arlington Cemetery? Go look at the graves of brave patriots who died defending the United States of America. You will see all faiths, genders and ethnicities."

"You have sacrificed nothing and no one," Khan added.

Speaking later with ABC News, Trump claimed that he had "made a lot of sacrifices," before turning on Khan's wife:

"If you look at his wife, she was standing there," Trump said. "She had nothing to say. She probably, maybe she wasn't allowed to have anything to say. You tell me."

The public backlash against these comments came swiftly. Politicians on both sides of the aisle are appalled at the callousness of belittling the family of a fallen soldier.

Republican officials, already lukewarm about the billionaire's candidacy, have hit back especially hard.

"This is going to a place where we've never gone before, to push back against the families of the fallen," Republican Senator Lindsey Graham (South Carolina) said in a statement. "There used to be some things that were sacred in American politics - that you don't do - like criticizing the parents of a fallen soldier, even if they criticize you."

"If you're going to be leader of the free world, you have to be able to accept criticism. Mr. Trump can't," Graham said. "The problem is, 'unacceptable' doesn't even begin to describe it."

"This is so incredibly disrespectful of a family that endured the ultimate sacrifice for our country," tweeted Jeb Bush, who ran against Trump in the 2016 Republican primary.

This is so incredibly disrespectful of a family that endured the ultimate sacrifice for our country.

— Jeb Bush (@JebBush) July 31, 2016

Ohio Governor John Kasich also weighed in on Twitter, "There's only one way to talk about Gold Star parents: with honor and respect." Kasich refused to attend the Republican National Convention in his home state, and refuses to endorse Trump. "Capt. Khan is a hero. Together, we should pray for his family."

Trump's Democratic rival Hillary Clinton, though, is not surprised. Speaking to reporters along with Vice Presidential candidate Tim Kain:

"Well, he called Mexicans rapists and criminals. He said a federal judge was unqualified because of his Mexican heritage. He has called women pigs. He has mocked a reporter with a disability."

"Ridiculed a POW in John McCain," Kaine added.

"That's right," Clinton jumped back in.

"And any one of those things is so offensive and then to launch an attack as he did on Capt. Khan's mother, a Gold Star mother, who stood there on that stage with her husband honoring the sacrifice of their son and who has in the days since spoken out about the overwhelming emotion that any mother would feel as her son was being honored and then to have Trump do what he did, I don't know where the bounds are. I don't know where the bottom is."

Kaine's comment referred to Trump's previous criticism of John McCain's war experience last summer.

"I like people who weren’t captured," Trump had said. McCain was a POW during the Vietnam War.

In a published statement, John McCain lost his patience: "While our Party has bestowed upon him the nomination, it is not accompanied by unfettered license to defame those who are the best among us."

He continued, "I'd like to say to Mr. and Mrs. Khan: thank you for immigrating to America. We're a better country because of you. And you are certainly right; your son was the best of a America, and the memory of his sacrifice will make us a better nation - and he will never be forgotten."

Caroline McCain, granddaughter of John, and a Fox news analyst, says that Trumps statements have pushed her to go over to the other side and vote for Hillary Clinton.

"I understand the voters have spoken. I understand that he's had more votes than any other candidate – but this is an incredibly polarizing election. 60 percent of Republicans want another candidate. This is not the vision for America I have," she published on Thursday.

Trump, faced by the condemnation of a nation, continues to stick to his convictions.

Captain Khan, killed 12 years ago, was a hero, but this is about RADICAL ISLAMIC TERROR and the weakness of our "leaders" to eradicate it!

— Donald J. Trump (@realDonaldTrump) July 31, 2016