Lee has been embroiled in controversy after posting a response to the assassination of Minnesota lawmaker Melissa Hortman over the weekend. During his monologue Monday night, Stewart recounted his own experience with the GOP Republican.

His social media posts resemble those of a frequent user on right-wing message boards rather than those of a U.S. senator.

When there’s political violence in western democracies it’s traditionally treated as a somber event for everyone to come together. That’s disappeared. The victims were gunned down just over a day ago and a US Senator is mocking the event and hinting at a deranged conspiracy. https://t.co/EO7pbWI8ng