And it seems that no one is safe from it.
He was talking about opioids, including heroin and prescription painkillers, which are devastating communities across the nation.
Cut to a clip of Donald Trump wondering aloud how heroin could be a problem in a serene place.

Credit: HBO
And I said, How does heroin work with these beautiful lakes and trees?…
Yeah, it does, though, said Oliver, drawing laughs.
Heroin works basically everywhere because its heroin, not a cell phone.
Heroin has full coverage.
But however it starts, it can get out of hand fast.
Heroin is so much more cheaper, said one of the opioid victims.
This is happening everywhere, said Oliver.
So who is to blame for the crisis?
Oliver pointed fingers at the pharmaceutical industry and the Federal Trade Commission.
For his complete remarks, watch the video below.