Just when you thought you knew all about the furthest fringes of American political life, Bill Moyers takes note of a relatively new one: Christian reconstructionists, "who want to invent America all over again," this time according to what they think God wants it to be.

In "On Earth as It Is in Heaven," the conclusion of his superb "God and Politics" trilogy, Moyers talks with leaders of this ultraright faction who would replace democracy with theocracy and think everyone should subscribe to Christianity body and soul. The report airs at 9 tonight on Channel 26 and other PBS stations.

Rousas John Rushdoony, 71, a transplanted Armenian now living and writing in California, tells Moyers that democracy "is failing today" and that "the state is a bankrupt institution." His solution is a new society in which justice is meted out according to a literal reading of the Bible. That means the death penalty, he says, for rape, sodomy, adultery and homosexuality.

"This is what God requires," Rushdoony feels confident in saying. God also requires, apparently, "a hard-money economy" based on the gold standard and a "debt-free economy" as well. In other words, as Moyers elicits from Rushdoony, thou shalt have no 30-year mortgage before thee.

Rushdoony actually sounds the most reasonable of the reconstructionists Moyers encounters. Rushdoony's son-in-law, the prolific Gary North, is too radical even for him."We don't get along," Rushdoony says. North turned down Moyers' request for an interview.

The alternatives, one preacher insists, are "a humanistic state or a God-centered government," and another declares, "The choice is Christian morality or no morality." The reconstructionists appear to see capitalism as divinely inspired. A former Jewish Marxist who now heads a Christian businessmen's group in California says, "We'll win in the marketplace."

One small reconstructionist church visited by the camera has a lot of empty pews; that's reassuring. But an Atlanta "mega-church" that vibrates with charismatic revelry and reconstructionist rhetoric is thriving. Edwin Meese, the (for lack of a better term) attorney general, courted members of the movement by speaking at an evangelical Christian conference in September.

And, almost as ominously -- in some strange way -- Moyers reports that Mr. T, the bejeweled and bechained TV star, is among the true believers.

Talk of today's Christian-educated children being "the army that's going to take the future" is unnerving as well. One could laugh off the reconstructionists as ridiculists, but today's radical freak is tomorrow's Time cover. Moyers establishes beyond a doubt that the reconstructionists bear watching.

Producers Greg Pratt and Jan Falstad did a rather feeble job of adding visuals to the report; there are innumerable cliche'd views of Washington monuments and public buildings. Maybe if there were a church or religious symbol in the same shot these would make some sort of comment or contribution. As it is, they are just ornamental. Some of the computer graphic effects are jarring.

Moyers continues to scrutinize the toughest subjects with exemplary perseverance. True, he does feel the urge to sermonize at the end, but we've grown to expect that of Parson Bill. Mostly he lets the interview subjects tell their own story -- one that adds a little extra chill to the dry December air.