WASHINGTON — Jon Stewart and Stephen Colbert have revealed few details about Saturday’s “”Rally to Restore Sanity”” and/or “”March to Keep Fear Alive,”” a gathering on the National Mall, according to its official description, “”for the people who think shouting is annoying, counterproductive and terrible for your throat.””

But they have been explicit about one aspect: “”This is not a political rally in any way, shape or form,”” Stewart told Larry King last week.

Try telling that to Nanci Ponne of Chicago.

“”This event, while originally intended for jest, could possibly become a ‘turning point’ … in our nation’s history for having immense impact on how political discourse is engaged in the future,”” the 52-year-old writer and actress wrote on the event’s Facebook page this week. “”You have created a political movement, intended or not.””

Ponne is not the only one with high expectations. The announcement last month by the Comedy Central hosts that they would hold dueling rallies in Washington (now merged into one) triggered Web-based, grass-roots organizing reminiscent of the presidential campaigns of Howard Dean and Barack Obama.

The rally’s Facebook page is a hive of activity, much of it aimed at the political left, with posts about get-out-the-vote efforts and plugs for Democratic candidates mixed in with logistics advice. As of Wednesday afternoon, more than 223,000 people indicated they plan to attend.

Fans who can’t make it have set up at least 20 satellite “”Sanity”” rallies in cities such as Austin, Los Angeles, Chicago, Denver, Honolulu and Boise. MeetUp.com lists more than 1,100 local watch parties, including a live viewing at the middle school in Wasilla, Alaska, at 8 a.m. local time.

Organizers said the call for a more tempered political dialogue tapped into a large demographic that feels alienated by this year’s overheated partisanship.

“”Jon Stewart is a catalyst, but the fuel was already ready to burn,”” said Jim Baum, coordinator of the Seattle rally, who expects 5,000 people to show up.

Obama’s appearance Wednesday on “”The Daily Show”” — the first by a sitting president — underscored the perception that Stewart, with his brand of indignant satire, wields considerable political clout.

At the show’s taping, the president told Stewart he could have used the call for sanity at the beginning of his term. “”The one other thing that might have made a difference is if you had held the Rally to Restore Sanity two years ago,”” Obama said, adding: “”Can I just make a plug? Just to vote. Go out there and vote November 2nd.””

But it remains to be seen whether Saturday’s three-hour rally will sate the political hunger that Stewart and Colbert have sparked.

In recent weeks, Stewart has insisted that the event is not meant to counter conservative commentator Glenn Beck’s recent “”Restoring Honor”” rally or to mock the tea party movement. And he stressed that it is not aimed at bolstering the left.

“”I have no obligation to the Democrats or progressives or liberals or unions,”” he told host NPR “”Fresh Air”” host Terry Gross last month. “”We’re not warriors in their cause.””

In an interview, “”Daily Show”” executive producer Josh Lieb described the rally as “”a simple comedic call for calm.””

Lieb offered no hints of who would be on stage, quipping: “”Right now we are banking a lot on the Great Pumpkin showing up.””

Taking their small-screen humor to the wide expanse of the National Mall represents a sizable risk for the late-night hosts, who derive much of their humor from their outsider status.

“”They’re definitely walking a tightrope,”” said Amber Day, who teaches political satire at Bryant University. “”The danger absolutely is seeming to come too close to the things they critique.””

But fans of the duo believe they are the right messengers for the time.

“”To many, it might seem strange that a comedian could lead the march to change the level and tone of discourse in America,”” said David Todd Agro, a 32-year-old project manager in Brattleboro, Vt. “”However, at its best, comedy and satire reveal our foibles to us. We may chuckle, but then the absurdity sinks in and we may even begin to think.””

The anticipation for the rally, which will be broadcast live on Comedy Central and C-SPAN, speaks to the longing many Democrats and independents feel for the excitement of the 2008 campaign.

“”That’s part of what this is compensating for, that feeling that all the energy and motivation of people who volunteered during the Obama campaign went nowhere,”” said Shaun Treat, who teaches politics and rhetoric at University of North Texas. “”There’s a lot of genuine frustration with that.””

Still, it is unclear what, if any, political impact the event will have. While some Democrats have fretted that the rally could cannibalize get-out-the-vote efforts, other party strategists believe it could inspire some disaffected voters to go the polls, a feeling shared by many fans.

“”If Jon and Stephen can get people to go across the country to D.C., I guarantee you they’re going to get people to go down the street and fill out a ballot on Tuesday,”” said Ponne, who is planning on attending the Chicago satellite rally.

Others hope it will create a lasting voting bloc elected officials will have to heed.

“”For us, it is political,”” said Kathy Payne, 46, who is driving to Washington with friends from Venice, Fla. “”We want to show our numbers, that we really are a lot of reasonable people out here.

“”And if nothing else,”” she added, “”it’s going to be a great show.””