But many locals who plan to go to Washington Saturday - in carpools, chartered buses, packed trains - aren't laughing. Asked why they're going, they're dead serious.
"Because the political scene has become truly insane," Karen Kaplan of Ambler wrote in an e-mail.
Allan Lundy, 63, a research consultant in Wyncote, said, "The political discourse has been so nasty and negative that there has to be a countervailing current that's more moderate and more reasonable."
When did this rally cross over from clowning to protest? Can you have a joke if for thousands it's no laughing matter? Will real protests break out at a faux event?
The actual content of the rally had been secret, but the Washington Post reported Thursday on its website that musical guests would include the Roots, Sheryl Crow, and Jeff Tweedy and Mavis Staples.
Megabus, BoltBus, and Chinatown bus rides to Washington are sold out. Across the region - and well beyond - groups are organizing transportation.
Joanne Sonn belongs to the Wayne Coffee Party (as in the non-tea party?), which has chartered a bus, complete with "coffee and mimosas," from King of Prussia. Emma Ellman-Golan, president of the University of Pennsylvania Democrats, said her group's bus sold out about a week ago, "and there are four or five more buses chartered by a couple of the dorms."
Comedy Central, the TV channel that is the home of The Daily Show With Jon Stewart and The Colbert Report, has chartered fleets of buses. As of Thursday, DCrally bus.com, set up by the channel, listed 221 reservations on buses leaving 30th Street Station at 6:30 a.m. Saturday, and an additional 176 spots on buses departing the IMAX theater at the King of Prussia mall. (But are there mimosas?)
Others will leave from Bethlehem, Allentown, Harrisburg, and Pittsburgh. Philadelphian Caroline Leopold, a nonprofit worker, signed up to be a bus captain. She called the Comedy Central effort "unusual - it must be costing them a staggering amount."
"Why should the bitter, angry, irrational people have all the fun?" e-mailed Alan Turner, 53, of Wilmington, posing as a sweet, happy, rational fun-seeker. That's Stewart/Colbert-style humor, poking fun at the rage out there. But there's that . . . edge to it.
Linda Cook of Philadelphia likes the moderation angle: "The idea of advocating civilized discourse and respectful disagreement in the political arena moved me to action."
What's been dubbed a "million moderate march" will be televised on Comedy Central and streamed on its website.
Many rally-goers express mordant worry and frustration. "It's a little tricky," said Nancy Bedrosian of Glenside, "since it's kind of a send-up of a rally. However, I am frightened of political extremists and the media outlets that . . . feed their fears with distortions and half-truths."
Not smiley-face stuff.
Faces weren't exactly smiley Wednesday night when, in a sort of prologue to the rally, President Obama appeared on The Daily Show.
Welcoming but tough, Stewart lobbed cannonballs, not softballs: "You ran with such, if I may, audacity, yet legislatively it has felt timid at times," which drew a sharp comeback from Obama. Stewart painted Democrats as the tomcatting lover-man in a blues song: "Democrats this year seem to be running on 'Please, baby, one more chance.' "
Obama told him "Not true" at least once, and said, "Jon, I love your show," before knocking down a question. Never mind the oddity of a president going on cable TV six days before a midterm election; it was a fascinating tightrope walk for Stewart, who has been attacked (loving every moment) by conservatives for favoring the left and by lefties for not favoring the left enough.
Howard Kurtz of the Daily Beast website wrote, "I think Stewart passed the initial exam," but wondered whether any rally could live up to this much hype.
To be sure, some are going for the fun of it. That would include Easton, Pa., native Max Walker, 19, a student at George Washington University in Washington. "I watch both The Daily Show and The Colbert Report, and I'm going," he said. "Everybody I know is going. It's a fun, social thing to do; I'm not trying to make a point or anything."
Patrick Madl of Broomall is also at GW, in Stewart's old frat, Pi Kappa Alpha, in fact. He went to Beck's rally and is going to Stewart's. "This weekend will be a good time for many of the students here, including myself," he wrote.
Any rally mixes the serious and the fun. So it was in the 1960s, when protest often got mixed up with love-in. Lundy said, "I've been to a number of political rallies, and they tended to be a lot of fun even when they had an ostensibly serious purpose, so this one will be doubly fun."
Many are going to celebrate two of their favorite TV guys. Judy Lewis, 52, an Internet ad-agency editor in Glenside, is taking her two teenagers: "We all enjoy Jon Stewart and Stephen Colbert's smart, incisive, and, most of all, funny commentary on politics and American culture."
Then she got all serious: "I want to be there, surrounded, I hope, by like-minded people who want to share their belief in moderation, belief in the president, and their affection for . . . Jon Stewart and Stephen Colbert and their talented writers. They make us laugh and feel hopeful when the political and economic climate is harsh."
Like great clowns of the past, Stewart and Colbert know when to let ambiguity work for them. And their sense of political timing is superb.
Colman Byrne of Broomall knows that. He's taking his son, 12, "to share with him the long historical tradition of the jester pointing out the foibles of the powerful and to encourage a healthy cynicism and questioning attitude about everything he sees and reads (even in The Inquirer)."
No matter why people are going, enthusiasm runs high. Carol Rapier, a bus captain from Phoenixville, put it this way: "I missed Woodstock, so this is going to be it for me."
Contact staff writer John Timpane at 215-854-4406, firstname.lastname@example.org, or twitter.com/jtimpane.