Surely avuncular Walter Cronkite has played Santa Claus sometime during his long career -- the man's eyes twinkle, his chuckle has a "ho-ho-ho." Especially when he surmises that perhaps the reason more Americans than ever are going to church is that "they don't like Sunday morning television." Ouch. Ho ho ho.

This week before Christmas, on the eighth edition of "The Cronkite Report" (Wednesday at 10 on The Discovery Channel), the legendary newsman spends his hour looking at the growth of Christianity in this country. The title: "Christianity Reborn: Prayer and Politics."

According to Cronkite's research, the United States is one of the most religious countries in the world: 94 percent of Americans say they believe in God and more than 85 percent call themselves Christians. Some use the term for all people who follow the teachings of Jesus; others mean only the re-born evangelicals.

It is one of the knottiest problems: how any religion, which is exclusive, and democracy, which by nature is inclusive, can coexist in a pluralistic society.

In town recently to do interviews for that program, Cronkite confirmed that he is among those with roots in mainline Protestantism. Descended from Dutch-German Lutherans, he was born in St. Joseph, Mo., up the Missouri River from Kansas City, and attended the nearby Presbyterian Sunday school. Cronkite said his mother noticed on the day of his wedding that his bride, Betsy, carried a Bible just like the one Walter owned. It seems she had attended the same Sunday school Walter did when they were 5.

Now, he is an Episcopalian, but like many families, his has several facets: One of his children became a Quaker because of her anti-war views; a son is married to a Roman Catholic, he said, but sometimes attends Presbyterian services.

Before the November elections focused attention on the political clout of the Christian right, Cronkite and producer Sandy Sokolow, his longtime CBS News colleague, had begun the research and interviews for this program.

"We weren't going to concentrate on the religious right, feeling that was a fairly well-explored subject -- or would be by the time we got on the air after this last election, whether they won or lost," said Cronkite. "Our thrust is primarily why there is a resurgent interest in religion at all in this country. The fact is that in the United States, church attendance is on the upswing, particularly compared to other industrialized nations, where it's really plummeting. Churches are folding practically all over Europe. So we wanted to look into what was it about the American spirit that was driving people back to religion?

"But the more we got into it, the more we kept getting involved with the religious right situation and people's interest in the religious right and its obvious organizing effort in spreading the word across the country. The first question simply was: Has the religious right helped inspire this return to church or is it exploiting it? Call it the chicken-or-the-egg factor. I don't think we've come to a conclusion. It's something of both.

"Exploitation is a word that I'm sure the Christian right would object to, but certainly their appeal, the massive organizational effort, is aimed at people who are church attenders, who are looking to their faith for something."

The 16 interviews for the program include Ralph Reed, executive director of the Christian Coalition, and the Rev. Joan Brown Campbell of the National Council of Churches. But it also offers a prickly roundtable discussion involving the Rev. Robert Meneilly of the large Village Presbyterian Church in Prairie Village, Kan., who had preached against the Christian right; a former state senator who directs the Mainstream Coalition; and two opponents, a columnist-commentator and a Christian-right organizer.

"I hardly had to say a word," remarked Cronkite, with that chuckle. "All we had to say was 'the camera is rolling' and they were at each other's throats. But it was a very interesting discussion.

"There's a split between evangelicals, who believe they have the word, and those who are a bit more conciliatory and allow for the possibility that somebody else may have the word as well."

In Village Presbyterian, outside Kansas City, Cronkite and Sokolow "found a church that was an absolute perfect example of what is happening to churches all over the United States today in the split between the evangelical right and the more mainstream. We've got this wonderful dichotomy right there in this typical heart-of-America community."

Cronkite also looks at evangelical, nondenominational Willow Creek Community Church near Chicago. Drawing 15,000 people each Sunday, Willow Creek has no religious icons, stained glass or prayer books, but draws young, affluent, suburban professionals who respond to a Bible-based theology.

It is what Cronkite calls the "mega-church," a "church-mall," a "supermarket spirituality." Its services are multimedia presentations, including drama and music with high-tech packaging; and it offers 800 study and support groups.

"I've kind of come to a conclusion about what is drawing people to church today, and there are several things involved," Cronkite said. "One is the services the churches are rendering. They've got all kinds of programs. I think that the Rev. Meneilly said Village Church in Kansas City has 18 social service outreach programs, everything from marriage counseling to AIDS counseling to day-care centers, all this sort of thing. The church has become in many ways a community center again in the life of America. That has a lot to do with it.

"I really feel that the underlying drive is {that} these people are looking for an anchor to windward. There's something they remember from the past vaguely that they can hold on to, something where the values have been constant in the world of changing values. And I think that's what is really bringing them back.

"I'm surprised at the number of my friends who do attend church today that I wouldn't have thought . . . that I don't think have been lifelong churchgoers."

After "The Cronkite Report" airs this week, Walter and Betsy Cronkite will head for Austria for PBS's "From Vienna: The New Year's Celebration," airing via satellite on Jan. 1 at 2:30 p.m. Cronkite will host the show for the 11th time.

"It's great fun," he said. "Vienna is wonderful at New Year's. Often we've had marvelous snow just as we arrived for Christmas and New Year's. Vienna is marvelously quiet at the first snowfall when traffic hasn't built up again."

At one time, Cronkite, now 78, hoped to become the first journalist in space. "It was suggested that the fix was probably in and I was going to get it," he said. "I don't believe that's really so, but I felt that I had a pretty good shot. The only thing that we had not gone through was the physical, and I was one of the older applicants.

"Then the Challenger disaster occurred. That was the flight we would have been on except for the politics of the situation. President Reagan, in attempting to repay the teachers for what he hoped would be their support, had promised that a teacher would be the first civilian in space.

"A lot of people asked me at that time if that changed my mind about wanting to go. It didn't change my mind at all about wanting to go. I thought they'd be even more careful with the next one. But I did say that I think it's a race now to get their plumbing fixed before mine goes."

Ho ho ho. Happy holidays, Uncle Walter.