Stephen Colbert started Monday’s The Late Show with a call for President Donald Trump to act forcefully on “common sense gun legislation” in the wake of the Las Vegas mass shooting, the deadliest mass shooting in U.S. history.

“Obviously, this is a comedy show but it’s one that talks about what happens every day. And today the national conversation is about the shooting in Las Vegas. And jokes aren’t appropriate to express the shock and the grief and the anger we all feel,” Colbert said. “But I do want to take a moment before we begin the show to say that once again, we want to send our thoughts and prayers to the victims and their families and everyone who was hurt by this unimaginable cruelty. Now, terrible things happen in the world. Sometimes, like today, we feel like they’ve risen to a new level. But we cannot accept that as a new normal.”

Colbert said he agreed with Trump’s own words that the shooting, which left 59 dead and more than 500 injured was “pure evil,” but had a follow-up question: “So what then are we willing to do to combat pure evil? The answer can’t be nothing. It can’t.”

The Late Show host and prominent Trump critic then cited the mass shooting in Alexandria, Virginia, this past summer, which left Republican congressman Steve Scalise hospitalized. “Last week, Representative Steve Scalise returned to the floor and was greeted with a bipartisan hero’s welcome. It was the kind of moment that gives you hope that Congress might work together for the common good,” Colbert said. “The bar is so low by now that Congress can be heroes by doing literally anything: universal background checks, or come up with a better answer; enforce Obama’s executive order that denied mentally ill gun purchases or a better answer; reinstate the assault weapons ban or come up with a better answer. Anything but nothing. Doing nothing is cowardice. Doing something will take courage.”

After discussing the courageous actions that occurred during the Las Vegas shooting, which happened during the Route 91 Harvest Festival while country singer Jason Aldean performed, Colbert spoke directly to Trump.

“Now, President Trump, you’ve said you want to be a transformative president, who doesn’t care about the way things have always been done in Washington D.C. This is your chance to prove it,” Colbert said. “And I mean this sincerely. You do not owe the Republicans anything. You know the Republicans tried to stop you from being president. Well, screw ’em! You want to make America Great again, do something the last two presidents haven’t been able to do: pass any kind of common sense gun legislation that the vast majority of Americans want. Because if we are facing pure evil, then, by all means, offer thoughts and prayers. But think about what you need to do and then pray for the courage to do it.”