Bill Moyers has found the heart of the evangelical political movement and exposes it tonight on "Bill Moyers' Journal: Campaign Report," at 9 on Channel 26. The hour is the best and least hysterical study yet done of the newly congealed constituency that embraces political conservatives and Protestant fundamentalists and wants to force a return to simpler times.

"This country needs to be turned around," believers repeatedly we tell Moyers or testify from pulpits. Turned around and marched backward? So it would seem, and much of what is said by the evangelicals on the program hardly sounds humane or compassionate. Demons and friends are blamed for the country's troubles, and the federal government is excoriated for meddling in personal matters on the one hand and yet urged to promote and sanction "prayer in the schools" on the other.

Ugly aspects of the movement have been paraded on such reports as the "60 Minutes" season premiere last Sunday and the current and excellent Jim Wooten series on ABC's ever-improving "World News Tonight." But Moyers bring an especially sensitive approach to the subject, and probably not just because he considers himself a "born-again Christian," previously the subject of one of his outstanding CBS News broadcasts.

Most of the report was taped at the big fundamentalist confab in where-else-but-Dallas, right-wing epicenter of the nation, and there are chilling over-tones to be sure. TV evangelist James Robinson thunders about "immoral, perverted special interest groups" and equates liberals with leftists with Communists with homosexuals. He tells the devout that their "wealth" is threatened by the government; nowhere does he appeal to anything that might pass for selflessness.

Bailey Smith, president of the Southern Baptist Convention, tells the crowd, "God almighty does not hear the prayer of a Jew, for how in the world can God hear the prayer of a man who says Jesus Christ is not the true Messiah?" From this same podium Ronald Reagan later accepts the endorsement of the fundamentalists and spouts some pandering placation.

But in talking with some of the people who attended the meeting, Moyers also hears legitimate, heartfelt concerns. Threats to the family unit are repeatedly mentioned, and who can blame people for wanting to find culprits? As for matters like abortion and ERA being not political but moral issues, a Christian Voice leader says, "The other side politicized the moral issue," and one can appreciate his point.

A man selling books that rate members of Congress on their "morality" sounds a bit like, others who spout mere rhetoric at Moyers during some of the interviews, but then he gets to the subject of his own family and the ways he feels it is endangered. "I got a 3-year-old, I got a 9-year-old and I got a 10-year-old," he says, and at that point he nearly breaks down weeping.

Some may find this movement frightening, but in fact it is a haven for a great many frightened people.

Moyers appropriately ends with a personal reaction. "I recognize deeply within me the inherited yearning for order and authority that cause us in menacing times to cling ever more tenaciously to the anchor of the faith," he says, and he points out that when it comes to using the church to sway the state, there are "precedents aplenty" -- including President Carter's showy trips to churches in back neighborhoods, and left-wing activism led by William Sloane Coffin and others with "Rev." before their names.

"It is not that the evangelicals are taking politics seriously that bothers me," Moyers says. "It's the lie they are being told by the demagogues who flatter them into believing they can achieve politically the certitude the have embraced theologically."

This "Moyers' Journal" is a thoughtful and important report.