The lead organizer of Gun Appreciation Day, gun-rights backers’ most prominent public effort to fight off gun-control legislation, helps run a group that warns of “armed government oppression” and a “world government.” Another group involved in the event stokes fear that “Barack Hussein Obama” will impose “martial law.” A third promotes a fringe constitutional theory beloved by the Tea Party, and a post on its website describes public schools as “progressive indoctrination camps.”

Gun Appreciation Day has received widespread media coverage since it was announced Monday. As Washington mulls tighter gun laws, the event aims to bring out gun owners to gun stores, gun shows, and firing ranges across the country, in an apparent effort to demonstrate broad, mainstream support for gun rights. Its website, which says it hopes to reach 50 million Americans, shows two well-groomed and smiling blonde women at a firing range. But several of the groups that are centrally involved traffic in some extremist conspiracy theories that are popular on the far-right fringes of the political debate.

Gun Appreciation Day, planned for January 19, is being spearheaded by Larry Ward, who runs Political Media, a Washington, D.C.-area Republican media consulting firm, specializing in online campaigns. Many of the early participants in the event have ties to Ward or Political Media.

Alan Gottlieb, whose Washington-state-based group, the Second Amendment Foundation, is another backer of Gun Appreciation Day, told msnbc.com that the response from gun owners and gun-rights supporters to the announcement of the event has been overwhelming.

“It really struck a raw nerve” among ordinary gun-owners, Gottlieb said.

But some of the “sponsors” listed on the event’s website (scroll down for a list of sponsors) appear motivated in part by the kind of outlandish and paranoid ideas often found among right-wing extremist groups.

One, the Social Security Institute, describes itself as a “nonpartisan seniors advocacy organization.” But its website offers warnings about “world government”—a bête noire of the extreme right, which fears that a government gun grab could lead to a U.N. takeover, often referred to in extremist circles as a “New World Order.” And SSI’s president, Lawrence Hunter, wrote recently that “[a] heavily armed citizenry is not about armed revolt; it is about defending oneself against armed government oppression.”

Ward, Gun Appreciation Day’s chief organizer, is listed as a member of SSI’s board, and as the group’s “director of new media.” The website for his company, Political Media, displays SSI’s site as an example of its work. Ward describes himself in his bio on SSI’s site as a protégé of GOP political consultant Dick Morris. Morris himself said last year on Fox News that he feared Obama would try to make the U.S. “a vassal state to a globalist entity.”

Ward, who did not respond to a request for comment from msnbc.com, popped up at an anti-NRA protest last month, telling demonstrators and reporters that the Newtown, Conn. shootings could have been stopped if teachers were armed, according to a Washington Post report.

Another listed sponsor of Gun Appreciation Day, RightMarch.com, urges supporters to “help STOP Barack Obama from grabbing unconstitutional powers to declare martial law through all of his new Presidential Executive Orders.” The notion that the federal government will confiscate guns as a precursor to a declaration of martial law is a feature of numerous far-right conspiracy theories.

And a post on the website of Conbustible.com, also listed as a sponsor of the event, describes public schools as “progressive indoctrination camps,” and complains that “the givers (sic) shove the producers out of the way as they waddle to the trough for some more free lunch.”

Another post on the site, which is affiliated with the Ron Paul movement, promotes the theory of nullification—that the 10th Amendment of the Constitution lets states “nullify” federal laws they don’t like. The idea, which has little backing among constitutional scholars, is a favorite of Tea Party activists opposed to healthcare reform and other Obama-administration measures, and has been embraced by neo-Confederate hate groups, according to the Southern Poverty Law Center, which tracks extremism.

One group not currently listed as a sponsor of Gun Appreciation Day: the NRA. Asked whether organizers had invited them to get involved, Gottlieb said they had, but hadn’t heard back.

“You know, it’s hard to get the NRA to return your calls,” he said.