John Oliver explained the impeachment process and made his case for it in a 20-minute segment on Last Week Tonight.

Said Oliver: “[I]t seems the president obstructed justice, then obstructed justice again to obstruct the investigation into his obstruction of justice. It’s ridiculous. … I know that this might seem like a legal technicality, and a couple of phone calls that didn’t go anywhere, but here’s why this really matters: But for Don McGahn, Trump might have stopped an investigation into himself. And if a president can shut down an investigation, he can basically do anything with no consequences. It’s a big, big deal.”

“Every asshole succeeds until they finally don’t,” Oliver continued. “18 months before he resigned, Nixon had sky-high rating approval of 67 percent. Harvey Weinstein was winning oscars until one day he definitely wasn’t. James Holzhauer was stealing all of Alex Trebek’s money until one day someone finally put a stop to it.”

“I can’t guarantee that impeachment will work out the way that you want it to,” added Oliver, “but that doesn’t mean it’s not worth doing. Because if nothing else, we’d be standing by the basic, fundamental principle that nobody is above the law.”

He went on: “For any Democrat whose main concern is that pursuing impeachment could be the reason they lose in 2020, please relax. It’s just one of many ways the Democrats could lose. Maybe Trump is caught on tape saying the n-word, but then two weeks later, Elizabeth Warren accidentally calls a veteran a veterinarian, and people get twice as angry about that. There’s so many ways that this could go wrong.