NEW YORK • The confrontation between the parents of a Muslim American soldier killed by a suicide bomber in Iraq and Republican presidential candidate Donald Trump has emerged as an unexpected and potentially pivotal flashpoint in the presidential election.
Mr Trump has plainly struggled to respond to the reproach of a military family who lost a son, and has answered their criticism derisively - first implying that Mrs Ghazala Khan had been forbidden to speak at the Democratic National Convention, then declaring that Mr Khizr Khan had "no right" to question Mr Trump's familiarity with the Constitution.
And his usual political toolkit has appeared to fail him, leaving him reeling amid a sustained campaign of criticism by the parents and a rising outcry within his own party.
Instead, Mr Trump appeared to be caught on Sunday in one of the biggest crises of his campaign.
Mr Trump and his advisers have tried repeatedly to change the subject to Islamic terrorism, but to no avail: In his latest attempt to deflect criticism, he posted on Twitter on Sunday that the real issue at stake in the election was terrorism.
However, he has not apologised to the Khans.
By going after a military family and trafficking in ethnic stereotypes, Mr Trump once again breached multiple norms of American politics, redoubling pressure on Republicans to choose between defending his remarks or breaking publicly with their nominee.
Mr Trump also risked reopening controversies related to religious tolerance and military service. The row has brought on a new wave of criticism of his proposal to ban Muslim immigration, and of his mockery of Senator John McCain's time as a prisoner of war in Vietnam.
Democratic leaders and candidates for Congress began over the weekend to call on Republicans to disavow Mr Trump. And the top two Republicans in Congress, House Speaker Paul Ryan and Senate majority leader Mitch McConnell, signalled their strong disagreement with Mr Trump, but stopped short of condemning him.
Democratic presidential nominee Hillary Clinton sternly reprimanded Mr Trump on Sunday morning, saying at a church in Cleveland that he had answered the Khan family's sacrifice with disrespect for them and for American traditions of religious tolerance.
"Mr Khan paid the ultimate sacrifice in his family, didn't he?" Mrs Clinton said. "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 Khans stiffened their denunciation of Mr Trump on Sunday, saying that he lacked the moral character and empathy to be president. Mr Khan, on NBC's Meet The Press, accused Mr Trump of running a campaign "of hatred, of derision, of dividing us".
And Mrs Khan, in an opinion article published in The Washington Post, said she did not speak at the convention because she did not believe she could remain composed.
She also rebuked Mr Trump as "ignorant" of Islam and criticised him for offering his business career as evidence that he had sacrificed for his country. "Donald Trump said he has made a lot of sacrifices," she said. "He doesn't know what the word sacrifice means."
It is too soon to say how severe the damage to Trump might be, but the clash has already entangled him in a self-destructive, days-long argument with accusers. It also threatens to unwind any progress he may have made at moderating his campaign and rallying his party at the outset of the general election.
And so far he has flailed and faltered in response.
NEW YORK TIMES