This afternoon, groups of angry conservatives will gather on street corners and in parks across the country to protest.

They will carry signs and deliver speeches expressing outrage over the Democrats’ stimulus bill, over entitlements, over budget pork, over taxes. They will dump boxes of tea on the ground and wear three-cornered hats. The leading lights of the Republican Party will be on hand to cheer them on.

But as with so much on the right, these apparent displays of populist rage are not what they will seem.

Six weeks ago, two of us (Mark Ames and Yasha Levine) published an investigation exposing the nascent “Tea Party” protest movement for what it really is: a carefully planned AstroTurf (or “fake grassroots”) lobby campaign hatched and orchestrated by the conservative advocacy organization FreedomWorks. Within days, pieces of the scam had crumbled, exposing a small group of right-wing think tanks and shady nonprofits at its core.

The Tea Party movement was born on Feb. 19 with a now-famous rant by second-string CNBC correspondent Rick Santelli, who called for a “Chicago Tea Party” in protest of President Barack Obama’s plans to help distressed American homeowners. Santelli’s call blazed through the blogosphere, greased along by a number of FreedomWorks-funded blogs, propelling him to the status of a 21st century Samuel Adams — a leader and symbol of disenfranchised Americans suffering under big-government oppression and mismanagement of the economy.

That same day, a nationwide “Tea Party” protest movement mysteriously materialized on the Internet. A whole ring of Web sites came online within hours of Santelli’s rant, like sleeper-cell blogs waiting for the trigger to act, all claiming to have been inspired by Santelli’s allegedly impromptu outburst.

At first glance, the sites appeared to be unconnected and unplanned. But many were suspiciously well designed and strangely on point with their “nonpartisan” and “grassroots” statements. It was as if all of them were reading from the same script. The Web sites heavily linked to each other, spreading their mission with help of Facebook and Twitter feeds. FreedomWorks, as if picking up on rumblings coming from the depths of the conservative netroots, linked to them, too.

But as our investigation showed, the key players in the Tea Party Web ring were no amateurs, but rather experienced Republican operatives with deep connections to FreedomWorks and other fake grassroots campaigns pushing pro-big-business interests.

FreedomWorks has a long history of using such campaigns. Founded in 2004 by Dick Armey, the former Republican House Majority Leader and lobbyist from Texas, and publishing titan Steve Forbes, FreedomWorks represented the consolidation and rebranding of two older think tanks, Citizens for a Sound Economy, founded by the notorious Koch family, and Empower America, a powerful lobbying firm that has battled health care reform and minimum-wage bills while championing deregulation, corporate tax cuts and whatever else their corporate clients desire.

The idea was to bring these two dinosaurs into the Internet age so they could compete with the newly created MoveOn.org.

Dick Armey goes grassroots with two tax-free money honeys in Arizona

FreedomWorks got caught AstroTurfing their sponsors’ agendas almost as soon as the group was formed. In 2005, when President George W. Bush was trying to get the public to go along with his plans for handing Social Security over to Wall Street bankers, the New York Times revealed that a “regular single mom” paraded by Bush’s White House in its PR campaign was in fact FreedomWorks’ Iowa state director.

Last year, the the Wall Street Journal exposed FreedomWorks’ role in sponsoring AngryRenter.com, a site designed to imitate an amateur blog with a plutocrat’s agenda: to shoot down a $300 billion bill meant to help distressed American homeowners. Freedomworks and its clients understood that if the superwealthy Republicans who opposed the bill were fronting the campaign, it wouldn’t fly with regular Americans buckling under the housing crisis, so they set up Angryrenter.com to give the impression that millions of ordinary Americans were the ones opposing it. The bill passed, but AngryRenter.com served as a warm-up exercise for the Tea Party movement.

The Tea Party improved on the AngryRenter.com model by diversifying its AstroTurf assets. Rather than put all its efforts into one vulnerable strategic entity, FreedomWorks distributed its campaign across a network of smaller, seemingly independent blogs and sites. If one was outed as a fake, the rest of the machine could deny affiliation and survive.

But what reeked of AstroTurfing on the Internet also reeked on the street, when protests hit over 30 cities across the country on Feb. 27.

In Santa Monica, Calif., the crowd was no bigger than the kind that mills around taco trucks at lunch hour. Other locations reported the same pathetic tally. In Cobb County, Ga., which should have been teeming with outraged freedom-loving, small-government activists, turnout was only marginally better.

It was clear that this grassroots movement was meant as a TV-only event. In the following days, as our article generated controversy about who really backed the Tea Party, FreedomWorks came clean and admitted to staging the whole thing. Santelli, the movement’s own larger-than-life hero, published a lawyer-crafted statement on CNBC’s site renouncing his role in the rebellion and throwing himself at the feet of Obama.

It was a crushing and humiliating blow to see the movement’s leader buckle so quickly, as if Adams had rushed to King George’s palace, three-pointed-hat in hand, and threw himself at the monarch’s mercy. To add to the humiliation, Santelli’s appearance on the Daily Show was canceled, and his employer, CNBC, soon became the laughingstock of the American network TV world.

The Tea Party movement seemed like it was dead in the water. But what seemed to be another failed FreedomWorks project came back one month later with a vengeance.