When he was paroled from prison last Christmas Eve, Willie Carter Spann promised to walk the line. The 33-year-old nephew of President Carter had a new wife, Jane Frey, a 41-year-old insurance broker he had wed in a prison ceremony eight months earlier. Spann hoped to join the lecture circuit to warn America's youth that crime doesn't pay, drawing on his jail experiences after he robbed a San Francisco bar in 1976.

As he left the California Medical Facility at Vacaville, Spann was picked up by a limousine, courtesy of the National Enquirer. The tabloid contracted to pay Spann several thousand dollars for an exclusive interview. But while the Spanns passed the time (until the newspaper published Willie's story) in Key West, he drank a little too much Wild Turkey, and an argument with an Enquirer reporter ended only after Spann "smacked" him. The newspaper canceled its deal, and Jane Spann returned to California alone.

Span spent the rest of January appearing on national talk shows discussing his role as "the bad peanut" in the Carter family. Today he says he has no contact with his mother, Gloria Carter Spann; he has talked once since he left prison with his uncle, the president and corresponds regularly with has grandmother, Miss Lillian. "We're a lot alike," says Spann, "both hard-headed."

When he returned to Cafifornia, Spann says he quarreled wit his wife after sipping some more Wild Turkey.

"I pushed her across the room, and the next day . . . she and her cat were gone," says Spann. He says she reported the fight and the drinking bouts to his parole officer, and he spend six seeks in a San Francisco jail for violating parole.

Now sparated, Spann lives with a girlfriend in Seabastpool, Calif., while he feeds chinchilas, drives trucks and cuts timber for a local company.

"We live way out in the country," says Spann. "It's real green, the people are kind of laid-back, and a bunch of bikers live next door. I'm trying to think positive."

He is also trying to make a recording. Two women in Atlanta wrote music and lyrics for a song called "I've Been at the Bottom Before," and Spann's agent, Washington-based Wayne Smith, hopes to produce a hit.

"Willie has the looks, and he can handle anybody from Phil Donahue to Tom Snyder," says Smith, who hopes Spann can go straight and develop a career as a lecturer or singer. If he succeeds, Spann says he has an invitation to visit his uncle in the White House. "He told me as soon as I got myself together, his hand would always be out."