The proper (and only decent) comment that Trump could have made to that is to agree -- that he has not suffered the great loss of Mr. khan and his wife, and respects the service of their heroic son and honors the sacrifice they have made.
But Donald Trump (caricatured here by DonkeyHotey) is not a decent human being. He is a thin-skinned narcissist who cannot take the slightest rebuke. So he attacked the Khan family. When that didn't work, he than tried to claim that he too has "sacrificed" for this country.
In an interview with George Stephanopoulos, Trump said the following when asked how he had sacrificed:
“I think I've made a lot of sacrifices. I work very, very hard. I've created thousands and thousands of jobs, tens of thousands of jobs, built great structures. I've had tremendous success. I think I've done a lot.”
What an outrageous statement! He has the audacity to compare his capitalist ventures with a family losing a son in war? That is especially ludicrous when you consider that all of those "sacrifices" made him a tom of money -- many times by paying sub-par wages, union-busting, and importing foreign workers. That's not sacrifice. That is GREED.
Do we really want a president who sees his own greed as sacrificing for his country? Trump should be ashamed of himself. The problem though, is that he has no shame -- only naked ambition, unbridled greed, and an immense love of himself.