Tell a joke to a liberal. Between your punchline and his laughter, there is a Progressive Comedy Pause. In this second or two, the liberal will process the joke to make sure he is allowed to laugh.

Is that joke racist? He mentioned Obama, but didn’t make light of him, so to speak. He also mentioned Michelle, but I didn’t notice sexism. Is it dismissive of the LGBTQIA community? Latinos? Muslims? Vegans? Will this joke hurt progressive causes? Will my laughter trivialize oppressed communities? Will I appear intolerant? I think it’s okay if I laugh. Yes, I’ll laugh now to signal my appreciation and to indicate that I’m not a joyless liberal scold.

“Ha ha.”

I first noticed the Progressive Comedy Pause while sharing my hilarity at office staff meetings. The majority would laugh but the committed lefties would stare blankly, each eye like that spinning wheel your smartphone shows while an app is loading. (The PCP might be why progressives just hoot and clap at Bill Maher’s jokes; the laughter reflex is considered problematic.)

What’s an annoyance in a business meeting is deadly to stand-up comedy. Social Justice Warriors regularly screech about thoughtcrime on Saturday Night Live, The Daily Show, and anywhere else jokes are told. Comedians are now afraid to set foot on campus — traditionally the preferred venue to test material and build a following — because political correctness has become so toxic.

Jerry Seinfeld told ESPN Radio’s Colin Cowherd that his friends Chris Rock and Larry the Cable Guy have stopped performing at colleges:

”I don’t play colleges, but I hear a lot of people tell me, ‘Don’t go near colleges. They’re so PC,'” said Seinfeld. He continued, “I’ll give you an example: My daughter’s 14. My wife says to her, ‘Well, you know, in the next couple years, I think maybe you’re going to want to be hanging around the city more on the weekends, so you can see boys.’ You know what my daughter says? She says, ‘That’s sexist.’” Seinfeld said college students don’t understand racism and sexism. “They just want to use these words: ‘That’s racist;’ ‘That’s sexist;’ ‘That’s prejudice.’ [sic] They don’t even know what the [expletive] they’re talking about.”

It’s harder to laugh when you’re scared and much of the left is terrified. They know that an inappropriate chuckle, the wrong tweet, or last year’s term for an aggrieved minority can lessen their standing with progressive peers, if not get them fired from a job. Lefties also have turned the negative of humorlessness into the positive of moral superiority. Sniffing “That’s not funny!” at an inoffensive Caitlyn Jenner joke signals that you are more evolved than the average cis-het-white-oppressor. The same people who laughed at Dana Carvey’s “Church Lady” now aspire to be her.

Unfortunately for Seinfeld, I expect this trend to get worse. Progressive conferences instruct their attendees about all the jokes that are off-limits. At last year’s Netroots Nation, professional “humorists” offered to review jokes to ensure they didn’t harm disenfranchised communities. At the three-day event, I rarely saw an attendee crack a smile, let alone laugh.

More and more, comedians are realizing that their progressive allies are the ones trying to silence them, not those unsophisticated conservatives comics love to mock. Perhaps comics should seize this opportunity to joke about humorless liberals before it’s too late.