On Sunday night, John Oliver dedicated the main story of Last Week Tonight to laying out the case for impeaching President Trump.

Though impeachment isn’t popular with the public—a majority of Americans currently do not support impeachment proceedings, as House Speaker Nancy Pelosi has pointed out time and time again—Oliver argued that most of the public aren't aware of the contents of the Mueller Report. Impeachment could be a way of informing them, thus swaying public opinion.

“It is true that many people don’t fully understand what impeachment involves, so we thought tonight might be a good time to discuss what it is, why it may be warranted, and what the risks might be in carrying it out,” Oliver said.

While “impeachment in no way guarantees a president’s removal from office,” with no past presidents ever being removed due to impeachment, Oliver claimed that Trump had committed “high crimes and misdemeanors”—a treasonable offense. He pointed to the 10 instances of possible obstruction of justice outlined in the Mueller Report, including Trump’s repeated orders to then-White House Counsel Don McGahn to fire Special Counsel Robert Mueller, the person investigating him (which McGahn reportedly called “crazy shit”). If that weren’t enough, the report outlined how Trump then pressured McGahn to put out a statement denying that he’d tried to remove Mueller and wanted McGahn to write a letter to that effect for their records.

“To recap there, it seems the president obstructed justice—then obstructed justice again to obstruct the investigation into his obstruction of justice. It’s ridiculous,” said Oliver. “Here’s why it 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.”

But because this information has been out there for two months and failed to make a ripple, Oliver thinks the only next step is impeachment.

“When it comes to impeachment, there aren’t just two outcomes. Even if Trump is not removed, which he probably won’t be, the process could shine a light on the contents of the Mueller Report, potentially lead to new revelations about Trump’s conduct, and force his Republican allies to choose—publicly and on the record—whether or not to hold him to account,” Oliver explained.

“And you might well say, even so, opening an impeachment inquiry is just too risky, and I do get that. I’ve gone back and forth on this myself for that very reason,” he continued. “And to be honest, the thing that’s tipped the scales for me is remembering that not opening an inquiry comes with consequences too, because it essentially sends the message that the president can act with impunity, which is a dangerous precedent to set—not just for future presidents but for the current one.”

He then pointed to Trump’s recent interview with ABC News’ George Stephanopoulos, in which the president appeared to invite foreign interference in the 2020 election.

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