Last week, CNN's Sanjay Gupta, a neurosurgeon and one of America's best known doctors, came out in favor of medical marijuana. He also apologized for his earlier opposition to medical pot, and released Weed, a documentary about the medical benefits of cannabis. "The title Weed may sound cavalier, but the content is not," Gupta said.

Gupta is dead serious about his mea culpa and reversing long-held misconceptions about medical pot. And he's "a uniquely credible voice" in "the growing cacophony calling for the U.S. to rethink its drug policies," said Stephanie Slate at U.S. News. In fact, his coming out may be tipping point for marijuana in America, she said.

Regardless, America's late-night comics had a predictably lighter take on Gupta's about-face. Stephen Colbert at The Colbert Report had the most fun with the topic. (Watch above.) At his sister show, John Oliver playfully toyed with the idea of Dr. G smoking out with Erin Burnout and Wolf Spliff-tzer at the Cannabis News Network — before noting that this is in fact a serious story:

At NBC's Late Night, Jimmy Fallon tried to find photographic evidence of Gupta high on pot:

Conan O'Brien didn't really address the Gupta conversion, but he noted that in Colorado, one man is trying to get weed classified as a vegetable — a surefire way, O'Brien joked, to get Americans to stop lighting up.

Craig Ferguson at CBS beat the rush, actually having Gupta on his show in June. Since it's an interview, Ferguson's back-and-forth about medical marijuana made for probably the most interesting video of the bunch. If it's too serious, re-watch Colbert above: