Will a middle-aged Muslim couple finally bring down Donald Trump?

It could happen.

After all these months of bigotry, insults, bombast, trolling and lies — after week upon week of poll numbers that only rose with every outrageous slur — will it finally be Khizr and Ghazalah Khan who send the Republican candidate crashing to the ground?

Also Read: Donald Trump v The Khans: 5 Reasons His Latest Fight Is So Disastrous

At this point, I see it going one of a few ways: Trump could just bow out. The man does not like to apologize, and he doesn’t like to lose. But the self-proclaimed blue-collar billionaire increasingly finds himself boxed into a corner by a determined couple with no ax to grind and no incentive to back down. Under this much pressure he may just decide “Oh, just screw it,” and go back to his life of sacrifice building skyscrapers and firing people.

Or the Republican Party could find its cojones and ask him to step aside.

As Trump looks around the room, he sees an ever-diminishing number of allies. The sympathetic reaction across the nation to Khizr Khan’s moving speech at the Democratic National Convention has given way to national disgust at Trump’s callous responses questioning whether Ghazalah Khan was allowed to speak, and trying to redirect the conversation to “radical Islam.”

Increasingly, his own party members are rejecting him and even his running mate, Mike Pence, tried to embrace the Khans while not actually repudiating Trump on Monday. That, along with the statements of GOP congressional leaders Paul Ryan and Mitch McConnell, were exquisitely awkward.

Also Read: Ghazala Khan Fires Back at Donald Trump: 'My Culture Never Stopped Me Saying Whatever I Want to Say'

They also probably won’t hold as the din continues to rise. Military and veteran groups are calling out Trump’s behavior as “unacceptable.” The Clinton campaign is speechless and telling us so in so many words. The cable networks — though still not Fox News — are mining the subject through news cycle after news cycle with no end in sight.

On Monday, the longtime Republican strategist to Jeb Bush Sally Bradshaw publicly quit the party and said she would vote for Clinton rather than see Florida tip to Trump if polling in the state was close. On MSNBC a former Mitt Romney adviser Stuart Stevens said the party should ask Trump to step aside.

So let’s see: Trump has lost women, lost veterans, lost their families, lost the military, lost Latinos, lost Muslims and those who believe in freedom of religion.

Who does that leave?

The Khans, grieving parents of a fallen war hero, are the perfect foil to the paper-thin, overblown Trump. They are authenticity itself. They refuse to back down, they will not be mollified. Khizr Khan’s simple words — “you have sacrificed nothing and no one” — have left Trump sputtering, at a loss for his usual, insulting zingers.

Also Read: Veteran Groups, Gold Star Families Condemn Donald Trump Over Attacks on Khan Family

With the innocence of a child pointing at a naked emperor, the Khans say: America is too good for Donald Trump. We know America, they say. We have seen Trump. And he is not the man to lead the greatest democracy on earth.

To those words, spoken from the depths of sincerity and pain, there has come no reply.

What will Trump do? It is possible, and perhaps most likely, that the candidate will muddle through this controversy, bleeding supporters while doubling down on his appeal to undereducated, disaffected white men. But I wouldn’t be shocked if at any moment he just gave it all up. When challenged, bullies tend to cave — and usually when you least expect it.

In a modern-day David-and-Goliath moment, the Khans found the political giant’s weak spot and swung their slingshot: truth.

It remains to be seen if they can slay the giant. But the Khans’ aim is dead-on.