John Oliver is convinced Donald Trump's attack on Khizr Khan tells you everything you need to know about his judgement, or lack thereof.

"They are self-serving half-truths from a self-serving half-man who has somehow convinced half the country that sacrifice is the same thing as success," the "Last Week Tonight" host said of Trump's assault on Khan, the Muslim father of a U.S. Army captain killed in the Iraq War.

The two have engaged in a war of words ever since Khan took center stage at the Democratic National Convention and chastised Trump over an anti-Muslim platform that seeks to ban individuals like his son from entering the U.S.

Khan's Offensive

"Go look at the graves of brave patriots who died defending the United States of America," he said. "You will see all faiths, genders and ethnicities. You have sacrificed nothing and no one."

Trump countered by arguing his sacrifice has come in the form of the "thousands and thousands of people" he has employed and having earned "tremendous success."

He also suggested that Khan's words were not his own and had been written for him by staffers of Hillary Clinton.

"Honestly, the main takeaway from these two weeks is that, incredibly, we may be on the brink of electing such a damaged, sociopathic narcissist, that the simple presidential duty of comforting the families of fallen soldiers may actually be beyond his capabilities," Oliver added.

The HBO talk show host also took exception with Trump's boast that he now serves as "the voice" of voters.

"I am your voice is a fair claim. He does speak for some people," said Oliver. "Although, you would kind of hope that they would then react the way most people do when they hear their own voice, which is, 'Oh s-, I don't actually sound like that. Do I? That is f-ing horrifying."

Oliver Wonders About GOP 

Later, Oliver openly wondered why a "party that used to be organized around a set of shared principles is currently organized around one man" and how Trump manages to get away with saying so many controversial things.

"It's the bed of nails principle," he said. "If you step on one nail, it hurts you. If you step on a thousand nails, no single one stands out and you're fine. That is how Donald Trump has managed to say pretty much anything in this campaign, seemingly without consequences."