Ross Zimmerman Pierpont, retired surgeon and practicing curmudgeon, hit the campaign trail before Neil Armstrong walked on the moon. But after 10 failed campaigns, after sharing the Maryland ballot with candidates from Spiro T. Agnew to President Bush, 1990 was to have been a season of repose.

Then Pierpont got mad, really fuming, when he heard that William Seth Shepard, the retired diplomat Republican leaders recruited to run for governor, had chosen his wife, Lois, as a running mate.

Bad move, thought Pierpont. So at the behest of U.S. Rep. Helen Delich Bentley (R-Md.), also peeved at Shepard's decision, Pierpont did what he always does when he gets cranky: He filed for election. It's a response as reflexive for him as calling a radio talk show is for other disaffected Baltimoreans, and one Bentley knew she could count on.

"I had to save the embarrassment of the Republican Party having a candidate run for governor who feels insecure without his wife," Bentley said last week.

Shepard "gave us three days notice on this," she said. "You have to get somebody who can move very quickly, somebody who has had the experience of the wars and does not need a month to think about it."

So it was that on July 2, 15 minutes before the deadline, Pierpont went from being a campaign contributor of Shepard's to a potential spoiler in the Harvard law school graduate's anointment as party nominee. They will meet in the Sept. 11 primary.

Pierpont's 11th bid for office is his fourth for governor, and the second aimed at Schaefer. His platform includes abolishing most residential property taxes, greater use of the death penalty and a call that all candidates take AIDS and drug tests. He says the race, unlike some he has entered, is "doable."

"We'll prove to everyone that of all parameters I am the best candidate, whether that is scholastically, intellectually, in terms of management," said Pierpont, 72, who was the chief of surgery at Baltimore's Maryland General Hospital until his retirement in 1986. To Republicans turned off by the Shepards, "I look like the second coming," Pierpont said.

"They throw their arms around me. Sometimes they had treated me like I had fleas."

"I stepped from the plane and one lone campaign aide greeted me. Before I could say more than 'Hello,' he began to apologize for the small turnout. It seemed we had lost all visible support overnight . . . . I shrugged off the doleful response and held a press conference anyhow."

-- "Indicted," by Ross Z. Pierpont

He has never run without a reason.

He says George P. Mahoney's race-baiting drew him into the Democratic primary for governor in 1966. Two years later he opposed U.S. Sen. Daniel Brewster because, he says, Brewster drank too much. In 1970 he switched parties and ran against U.S. Rep. Clarence Long because Long was too much of a Democrat, and ran in 1974 against Sen. Charles Mathias because Mathias was not enough of a Republican. In between was a bid for mayor of Baltimore against Schaefer, and since then there were campaigns for governor in 1978 and 1982, and Congress in 1984, 1986 and 1988, the last two times in an effort to link U.S. Rep. Benjamin Cardin (D-Md.) to the state's savings and loan crisis.

In a sense Pierpont is on a roll. He has not lost a Republican primary since 1982, and he hopes two decades of name recognition will keep that streak intact when he faces Shepard next month.

"What Shepard did was submarine the whole party," Pierpont said. "The party looked foolish . . . Republicans have been battling a one-party state. How can we back a one-household state?"

Despite Bentley's defection, other top party leaders are sticking with Shepard, including Republican National Committeeman Dick Taylor and state House Minority Leader Ellen R. Sauerbrey (Baltimore County). But while Shepard's backers say he has some clear advantages in the race as a relatively new face, they concede Pierpont has a loyal following in spite of his 0-10 record.

Unlike some perennials, "I don't think he is viewed as a wacko," said Sauerbrey. "He has been around a long time. People like him. He is a good old shoe that is always showing up . . . . He also bears the burden of being a tired face because he has been around running for too long. That is a tough thing to overcome . . . . He may win. The primary is going to be a horse race."

From Pierpont's perspective, the early phase of his political career was one of near victory snatched away by party intrigue. There was the run against the overindulgent Brewster, who lost his seat to Mathias after Democrats refused to heed their better judgment and nominate Pierpont in the primary, Pierpont said. Or the 1974 race against Mathias, a lead-pipe cinch until Pierpont was indicted for illegal prescription writing. He was found not guilty by a judge, and in his 1982 book Pierpont said the charges were politically inspired.

In later years his campaigns have been more altruistic efforts, he said, to put a "sacrificial" GOP name on the ballot, or generate name recognition for other Republicans by forcing a primary election.

This time, he says he is out to win. Shepard isn't amused.

"To come in with 15 minutes left, when we have spent half a year trying to build the party, and then put it on a personal level, I just don't think it is going down well," Shepard said. "It was kind of given I would be the nominee. Now it is not a given. It is a probable . . . . It is time to start looking forward, time to start thinking like winners."