SALISBURY, MD. -- It's just noon, and perennial Republican candidate Ross Z. Pierpont is happily imposing himself on the fifth Eastern Shore radio station of the day.

At WDMV, in a cornfield south of here, he bullies newsman Mark Gardiner into taping an interview. Without benefit of questioning, Pierpont launches into a well-rehearsed attack on his gubernatorial primary opponent, William S. Shepard, for choosing his wife as a running mate.

"A divorce in office could be a catastrophe," says Pierpont, a 72-year-old retired Baltimore surgeon on his 11th Quixotic run for political office.

Having three other gubernatorial campaigns on his re'sume', Pierpont at least knows when he has an issue.

"This is great for me," he says in an interview, noting that he is on the ballot in next Tuesday's primary only because of the husband-wife team.

For Shepard and his wife, Lois, it has been a month of backing and filling. They explain repeatedly why they would make a good team at the Statehouse in Annapolis.

After shaking about 500 hands at the plant gate of Dresser Industries here, the Shepards are more confident that the political uproar over the "running mates" is subsiding.

"With Pierpont in the race, we have a primary opponent, so it will be able to play itself out," said William Shepard, 55, a former diplomat from Potomac. "If we win the primary, the issue is nullified."

Shepard was to have been the annointed Republican nominee. Beginning early this year, he courted and won party backing for what was expected to be at the minimum a respectable showing against Democratic incumbent William Donald Schaefer.

The unanimity among Maryland Republicans, already outnumbered almost 2 to 1 by Democrats, was shattered June 29 when he chose Lois Shepard to run for lieutenant governor.

Rep. Helen Delich Bentley (Md.), a Republican national committeewoman, denounced the choice and recruited Pierpont to oppose William Shepard.

"I didn't anticipate that degree of reaction one way or the other," Shepard says now. He says the uncertainty also has stymied his fund-raising. As of last week, Shepard reported $69,000 in campaign contributions, compared with more than $2 million for Schaefer.

But the Shepards also think they see a backlash to the backlash, as women begin to question why such adamant opposition arose.

There is also, they contend, a curiosity factor at work.

"Because of the innovative nature of the ticket, people want to hear more," William Shepard says.

Lois Shepard, who occasionally responds to questions posed directly to her husband, says the Republican unity built by her husband and state Chairman Joyce L. Terhes remains intact.

"There was a short time when it looked like it was going to fall apart, but it didn't," she said.

Yet, there is not much unity of opinion among party activists about the outcome of the primary, which is expected to draw a light turnout.

"I guess I'd call it a tossup," said Carol A. Arscott, chairman of the Republican Central Committee in Howard County, where strong GOP rumblings are being felt.

"I think that Ross, despite his late entry into the race, is well known, particularly in the areas where he's run before," Arscott said.

She acknowledged, also, that some of the Republican fury over the Shepard-Shepard ticket has died down.

Terhes, who has delicately hidden her personal feelings about the ticket, said the issue may have been blunted by the Baltimore Sun endorsement of the Shepards.

"I've had people call me and say initially they were very much against it, and their reaction was shock and almost anger," Terhes said.

"But when they have had time to think about it and see and hear her, they have come around and changed their whole perspective."

Baltimore County GOP Chairman Richard D. Bennett said he is far less certain that the grumbling has dissipated.

"People don't talk about it, but it's still a factor," Bennett said.

William Shepard has avoided a running debate with Pierpont, preferring to concentrate his attacks on Schaefer and what he terms the Democrat's overspending.

Last week he criticized the governor for being on a Far East trade mission while units of the Maryland National Guard were being called to active duty for the Persian Gulf crisis.

"Ross's attacks have been so personal," Shepard said. "If I started talking about him, I'd get angry. Besides, his ideas are all nonsense."

Lois Shepard said the primary can represent a turning point for the minority party in Maryland.

"The primary will decide whether we're comfortable with the old way, of having candidates at the top of the ticket who are there just to help the locals, or whether we want what we've done," she said, "which is jarring but new."

As usual, Pierpont, who has campaigned over the years to repeal the residential property tax, professes supreme confidence.

"I've got the whole party behind me," he says. "Bill thinks he's doing fine, but all he's got is a few old ladies."