Don't miss live coverage of Jon Stewart and Stephen Colbert's "Rally to Restore Sanity" and "March to Keep Fear Alive" tomorrow at 12 p.m. ET. Watch CNN.com/live or on your CNN App for the iPhone.

Washington (CNN) -- Comedy Central hosts Jon Stewart and Stephen Colbert will hold the "Rally to Restore Sanity" and the "March to Keep Fear Alive" on the National Mall on Saturday, with thousands expected to flood in from across the country.

The event comes months after conservative Fox News host Glenn Beck held a "Rally to Restore Honor" in Washington, in which thousands of conservatives and Tea Party faithful attended.

While Stewart has insisted that the rally is not a result of Beck's march, the event's Web pages appear to copy the look of Beck's event, and many say it's a direct response to Beck's often-controversial comments.

The rallies are, in essence, an extension of both comedians' shows. The "Daily Show" and "The Colbert Report" routinely blast Republicans, Democrats and the media for hyperpartisan attacks and outrageous and inflammatory innuendo.

"Republicans love America. They just seem to hate about 50 percent of the people who live in it," Stewart said on CNN's "Larry King Live" last week. "Democrats, for their thing, it's always: They love this country, they just somehow wish it were a different country. With Democrats, it's like, 'America is the greatest country in the world. [But] have you seen Finland's health care system?'"

Stewart began the week in Washington, hosting his show from a downtown studio. He interviewed President Obama on Wednesday, grilling him on the upcoming election and why Democrats seem to be disenchanted with the administration.

Read more about the Stewart-Obama interview

Colbert recently blasted Sean Bielat, the Republican running against Democratic Rep. Barney Frank, and Ken Buck, the Republican running in Colorado's Senate race, for their views on gays and lesbians. Buck linked being gay to alcoholism while Bielat said that gays and lesbians shouldn't serve in the military, just as short people cannot.

In his typical deadpan shtick, Colbert said, "Sean Bielat and Ken Buck can't help being politically opportunistic election year gay-baiters. They were born that way."

Humor aside, Stewart said the rally is for people who are "tired of their reflection in the media as being a divided country and a country that's ideological and conflicted and fighting, this is for those people."

See Time's photo gallery of Stewart and Colbert

"It's going to shock, maybe not even just this world, other worlds," he joked. "Maybe aliens."

The rally's popularity has gone viral -- from Facebook pages to local rallies in cities across the country. Several groups, including the liberal media blog Huffington Post and even daytime talk show queen Oprah Winfrey, have offered to transport people to Washington for the event.

One of the many in the crowd will be Heidi Thomas, a soccer mom from Virginia who is gathering some friends and heading to the rally.

"As soon as I heard about this, I knew I was going," she told CNN. "It was immediate. ... I got to the point where I was feeling very grumpy every night I'd go to bed because of the political tone and nature of the country right now."

Are you going? Share photos, videos and views about the rally.

Thomas said that after watching Stewart's show, she'd go to bed in a better mood, "because I'd feel like I wasn't going insane," adding that there were "actually sane people out there."

But things could turn to insanity when it comes to the bathroom situation.

Rally organizers are having trouble finding portable toilets for those attending, WTOP.com reports. Their event occurs the day before the Marine Corps Marathon, and organizers of that event have locked the 800 they have rented until Sunday morning.

Thomas is hopeful the rally will expose a segment of the population fed up with the political fringes.

"I think it's important to show that there is a majority or a lot of people who are feeling more moderate," she said. "It's just frustrating to me.

While Stewart says the rally won't be a partisan event, one media analyst wonders whether the rally will change Stewart from satirist to political activist.

"To me, the bottom-line question is this: Is this going to be a fun Saturday event with a lot of laughs?" said Howard Kurtz, host of CNN's Sunday program "Reliable Sources" and Washington bureau chief for The Daily Beast. "Or is it going to be something that, while wrapped in humor, is going to make a serious political point about folks in the middle -- moderates who are alienated ... by the partisan shouting on both sides?

"If that happens, Jon Stewart will have made a serious point while still having good fodder for 'The Daily Show.'"

CNN's Jason Hanna and Rachel Streitfeld contributed to this report.