Donald Trump's criticism about the Muslim parents of a slain American soldier has generated -- once again -- a backlash within his own party.
Just 100 days from the election, Trump has responded in his standard fashion -- dig in, claim he's being treated unfairly and attack back.
But the swift condemnation of Trump's response raises questions about whether this controversy is different from the ones that came before it.
This time, attacks from the Republican presidential nominee on the parents of a soldier who died defending America have put new pressure on GOP leaders to decide whether they will continue to stand by him. Already, the party's leaders in the House and the Senate have distanced themselves from Trump's remarks, and other Republican figures are attacking their nominee forcefully.
"This is going to a place where we've never gone before, to push back against the families of the fallen," Sen. Lindsey Graham, R-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."
The controversy is over Trump's response to Khizr and Ghazala Khan, whose son was killed in Iraq by a suicide bomber in 2004. The Khans took the stage Thursday night at the Democratic National Convention, where Khizr Khan rejected Trump's proposal to temporarily ban Muslims from entering the United States as unconstitutional, pulling a copy of the Constitution from his breast pocket and saying that Trump has "sacrificed nothing and no one." Trump has since responded by criticizing Ghazala Khan's silence and suggesting she wasn't allowed to speak.
The incident recalls Trump's attack last year on Arizona Sen. John McCain. Trump said at the time that McCain is not a war hero because he was captured and imprisoned in Vietnam. Many had speculated the criticism would spark Trump's decline in the GOP primary race -- it did not.
But there are two key differences: Trump was not yet the GOP nominee and McCain -- himself the 2008 GOP standard-bearer -- is a long-time public figure with experience parrying on the presidential level. The Khans are not.
"This is so incredibly disrespectful of a family that endured the ultimate sacrifice for our country," Jeb Bush, a Trump rival in the 2016 GOP primary, said on Twitter Sunday evening.
"There's only one way to talk about Gold Star parents: with honor and respect," tweeted Ohio Gov. John Kasich, who skipped the GOP convention in his state and has declined to endorse Trump. "Capt. Khan is a hero. Together, we should pray for his family."
Kasich's top strategist in his failed 2016 presidential campaign, John Weaver, tweeted a scathing attack on Trump's handling of the Khan controversy, saying: "Trump's slur against Captain Khan's mother is, even for him, beyond the pale. He has NO redeeming qualities."