The FBI undercover tapes of four North Georgia militiamen arrested Tuesday offer an extraordinary glimpse of the terrorism the group is accused of planning. Details of how they allegedly intended to commit mass murder with deadly ricin, carry out assassinations of officials, and bomb government buildings abound in government affidavits that directly quote the men talking to undercover informants.

But there’s one thing the affidavits don’t tell you: What did these four elderly Georgians allegedly hope to accomplish? About as close as you get to an answer is this cryptic quote from the alleged ringleader, 73-year-old Frederick W. Thomas: “When it comes to saving the Constitution, that means some people gotta die.”

Although the group is not mentioned in the court papers, the organization the men belonged to is certainly the Georgia Militia, which on its Web page identifies one of the accused terrorists, Dan Roberts, 67, as a contact. And the Georgia Militia is one of the hardest line such groups around, going far beyond most militias’ hatred of the federal government to traffic in open racism and anti-Semitism.

On its website, the Georgia Militia links to the usual array of conspiratorial materials from other antigovernment “Patriot” groups — but it also links to the Council of Conservative Citizens, a group that angrily opposes interracial marriage and has described black people as a “retrograde species of humanity.” Another link goes to American Patrol, a racist anti-immigrant hate group.

Also found on the Georgia Militia’s website is an essay, “Protocols of Zion & Freemasonry’s Final Revelation,” that extensively cites the Protocols of the Elders of Zion, a viciously anti-Semitic forgery that is nevertheless treated there as a revelatory text. Author Henry Makow discusses “the primitive Talmudic injunction to rule the world and usurp all its wealth, as outlined in the Protocols.” Elsewhere on the site, the Georgia Militia describes Israel as a “cancerous zionist [sic] entity” and refers to “our zionist occupied government that is controlled by powerful zionist lobbyists.” Zionist Occupied Government, or ZOG, is a phrase employed by most American neo-Nazi groups to describe the current federal government.

Then there are the alleged plotters themselves.

Thomas, the alleged ringleader, posted a Dec. 12, 2008, essay to a conservative website, Redstate.com, after Barack Obama was elected president but before he took office. Thomas speculated that if the Supreme Court found that Obama was not a U.S. citizen and therefore not eligible to serve, “[y]ou can bank on race riots the likes of which would make the L.A. and Watts riots look like a playground scuffle. Half the country would go up in flames.” A little later in the same essay, he added, “Personal property is destroyed by rioters to the tune of hundreds of millions of dollars every time a racial violent act garners national attention.”

Later, on June 29, 2009, Thomas speculated about who the government hated the most. “It’s not minority citizens this administration and the previous one fear. … It’s you the productive, the people that pay all the taxes, that earn the wealth.”

For his part, Emory Dan Roberts has a past as a neo-Confederate activist. In 2003, Roberts helped organize a protest in Toccoa, Ga., against attempts to change the Georgia state flag, which then included a small Confederate battle flag in its design. Speaking at his rally were members of the Council of Conservative Citizens and the racist League of the South. In 2004, Roberts organized another pro-Confederate flag rally outside a middle school in Stephens County, Ga. One of his fellow protesters was arrested after a rock was thrown at a school bus.

The FBI’s tapes of Roberts, Thomas and the other two alleged plotters — Samuel J. Crump Jr., 68, and Ray H. Adams, 65 — do not spell out what the men hoped to accomplish. But the fact that they belonged to a group that repeatedly expressed racial fears and animus suggests that at least part of their motivation was anger at the way America is changing into a more racially diverse country. The Census Bureau has predicted that white people will lose their majority in the U.S. by 2050, and this has helped propel the growth of hate and other antigovernment groups recently.

In fact, the Patriot groups began to grow explosively in 2008, when there were 149 such groups, in part because the emergence of Obama reminded many of the changing demographics of our country. That, plus the collapse of the economy at around the same time, helped drive an expansion in these groups, to the point where the Southern Poverty Law Center counted 824 in 2010.