In what Oliver called “the 53rd consecutive week Donald Trump was going to put his campaign back on track,” Trump delivered a speech last Monday outlining his tax proposals. But, the relatively wonky speech served as a mere appetizer to the rest of a week in which Trump later seemed to imply that some of his supporters could assassinate Hillary Clinton if she is elected in November. Later, Trump caused another firestorm when he claimed at a rally that President Barack Obama “is the founder of ISIS” and that Clinton is the “co-founder.”

Trump initially refused to walk back those comments, then later claimed he was being sarcastic and that he was referring to the foreign policy decisions of the president and the former Secretary of State.

Ratings challenged @CNN reports so seriously that I call President Obama (and Clinton) "the founder" of ISIS, & MVP. THEY DON'T GET SARCASM?

— Donald J. Trump (@realDonaldTrump) August 12, 2016

“Yes, ‘sarcasm’ is a bulls–t excuse,” Oliver said on Sunday night. “It’s the douchebag’s apology.” But, Trump then “made it so much weirder when, later that same day, he walked his walk-back back” in a speech where he claimed the statement was “not that sarcastic, to be honest with you.”

Even more troubling, Oliver said, was the fact that Trump also spent much of last week riling up his supporters by claiming the only way he can lose the November election is if the process is somehow “rigged.” Trump told supporters in Pennsylvania that Democrats can only win that swing state (where Democratic presidential nominees haven’t lost since 1988, and where Trump is trailing in polls) if they “cheat.”

“What is really worth taking note of there, and is worth thinking about, is that he’s suggesting the election may be stolen by his opponent—and that’s actually dangerous,” Oliver said on Last Week Tonight. The comedian then added that, while Trump is “talking the talk . . . he’s asking his supporters to walk the walk.” Oliver pointed to Trump’s campaign website, which (aside from soliciting donations, which Oliver strongly advised against) asks supporters to register to be a “Trump Election Observer”—a volunteer position that would seem to involve keeping an eye out for any Election Day impropriety at polling places.

Oliver said his team signed up for the position online and then received an e-mail in which the Trump campaign claimed, “We are going to do everything we are legally allowed to do to stop crooked Hillary from rigging this election.” Oliver called the claim “troubling, because I’m not sure Donald Trump knows what he’s legally allowed to do. His own attorney once had to apologize for saying ‘You can’t rape your own spouse.'”

https://www.youtube.com/watch?v=HJkaLpeKX08

Oliver ended his Trump-centric opening segment by mocking a video from later in the week in which the GOP nominee clearly returned to his infamous off-the-cuff speaking style at one of his rallies (despite Trump reportedly facing frequent calls from the GOP establishment to stay on message). Oliver narrated the video clip: “[Trump] picks up a chart and says, ‘Here’s a beauty.’ He then utters, with a straight face, the sentence, ‘I love charts,’ before unconvincingly claiming that only someone with ‘big, strong hands’ can hold a chart up. And, then he turns the chart back to [himself], as he’s clearly forgotten whatever the f— is printed on it.”

“Look,” Oliver gleefully continued, “I cannot wait for this campaign to be over. But, part of me is going to miss him when he’s gone.”