Donald Trump is facing mounting criticism from leaders of his own party, as a confrontation between the Republican nominee and the Muslim American parents of a soldier killed in Iraq continue to consume the presidential race.
Khizr and Ghazala Khan denounced Trump in ever more forceful terms, asserting Trump's temperament and lack of empathy rendered him unfit for office, while Trump claimed Khizr Khan "viciously attacked" him while speaking at the Democratic National Convention last week.
Khizr Khan repeated his call for Republicans House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell to repudiate Trump, saying they have a moral obligation to speak out against their party's standard-bearer.
In separate statements, Ryan and McConnell expressed support for the Khans and reiterated their opposition to Trump's proposed ban on Muslims, but neither mentioned Trump by name and neither abandoned support for the Republican nominee.
A string of prominent Republicans criticised Trump, while Democratic nominee Hillary Clinton used the episode to hammer him.
Speaking at a church in Cleveland on the third day of a post-convention bus tour, Clinton said Khizr Khan stood before his country to tell the story of his son, Captain Humayun Khan, who was killed by a suicide car bomb at age 27, and was denigrated by Trump.
"Mr Khan," she said, pausing, "paid the ultimate sacrifice in his family, didn't he? And what has he heard from Donald Trump? Nothing but insults, degrading comments about Muslims, a total misunderstanding of what made our country great."
The clash between the Khans and Trump has largely taken over the presidential race following both major party conventions and with less than 100 days until election day.
Whether the fight with the Khans will ultimately hurt Trump among voters remains an open question.
Some of Trump's more controversial remarks, such as his attacks on a disabled reporter and a US-born judge of Mexican descent, seem to have initially registered, only to fade somewhat quickly.
It's also possible that the controversy could help Trump, at least among those considering supporting him, if voters begin to see it as another example of elite-driven political correctness by the media and political establishment.
Yesterday, Khizr Khan said Trump disrespected his wife by insinuating that she wasn't allowed to speak at the convention because of the family's Muslim faith, and called on Republican leaders and voters to reject the GOP nominee.
"I implore those patriotic Americans that would probably vote for Donald Trump in November, I appeal to them, not to vote for hatred, not to vote for fear-mongering," Khan said on NBC's Meet the Press.
In an op-ed published in the Washington Post, Ghazala Khan directly responded to Trump, saying she was too distraught to speak at the convention and could barely control her emotions while walking on stage. "Here is my answer to Donald Trump: Because without saying a thing, all the world, all America, felt my pain. I am a Gold Star mother. Whoever saw me felt me in their heart," she wrote, using a term for the parents of fallen members of the military.
Trump and his campaign, meanwhile, sought to redirect the focus to the origins of the Iraq War and fears about Islamic terrorism. Trump first tweeted that "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!" And then: "I was viciously attacked by Mr Khan at the Democratic Convention. Am I not allowed to respond? Hillary voted for the Iraq war, not me!"
When pressed on CNN about what terrorism has to do with the Khan family, Trump spokesman Jason Miller said the campaign is trying to talk about a "broader issue".
Both Khans forcefully denounced terrorism yesterday, and Ghazala Khan said Trump was ignorant when it came to understanding Muslims.
Other Republicans were quick to criticise Trump.
New Hampshire Senator Kelly Ayotte, whose husband is a military veteran, said, "I am appalled that Donald Trump would disparage [the Khans] and that he had the gall to compare his own sacrifices to those of a Gold Star family."
Former Florida Governor Jeb Bush, who lost to Trump in the Republican presidential primary, lashed out at the businessman for suggesting that Ghazala Khan was not permitted to speak by her husband.
"This is so incredibly disrespectful of a family that endured the ultimate sacrifice for our country," Bush tweeted yesterday.
South Carolina Senator Lindsey Graham said the Republican nominee's attack on the Khans was unprecedented.
"This is going to a place where we've never gone before, to push back against the families of the fallen. There used to be some things that were sacred in American politics - that you don't do - like criticising the parents of a fallen soldier even if they criticise you," Graham said.
"If you're going to be leader of the free world, you have to be able to accept criticism.
"Mr Trump can't."
Mike Coffman, a veteran and Republican congressman from Colorado who has not endorsed his party's nominee, said in a statement: "Having served in Iraq, I'm deeply offended when Donald Trump fails to honour the sacrifices of all of our brave soldiers who were lost in that war."
This was not the first time Trump has made controversial comments about the US military.
Trump said that the nation's armed forces were a "disaster" during a debate, in response to a question about military spending. He said Arizona Republican Senator John McCain, a former prisoner of war, was not a war hero because he was captured. And he has been attacking retired Marine General John Allen, who spoke at the Democratic convention, for failing to defeat Isis.
Trump also drew criticism yesterday when he appeared to be unfamiliar with Russia's actions regarding Ukraine and its 2014 annexation of Crimea.
"He's not going into Ukraine, okay," Trump said on ABC's This Week of Russian President Vladimir Putin. "He's not gonna go into Ukraine, all right? You can mark it down. You can put it down."
Trump then appeared to contradict himself when George Stephanopoulos, host of ABC's This Week, responded that "he's already there, isn't he?"
"OK, well, he's there in a certain way," Trump replied.