Rufus Phillips, former CIA operative in Vietnam, international port and airport planner, former Fairfax Cunty supervisor, has in his middle age encountered the American Agriculture Movement (AAM).

The union has been an important one for Phillips because, in the estimate of Virginia Democratic campaign figures, it has raised his chances of being a U.S. senator from none to slim.

Phillips is one of eight candidates seeking the Democratic nomination to fill the seat being vacated by the retirement of Republican Sen. William L. Scott. When Democrats hold mass meetings in 136 cities and counties on April 15 to choose delegates to the June 9-10 nominating convention in Williamsburg, the Agriculture Movement generate delegates for phillips in a number of farm counties.

The support of the AAM comes in response to a Phillips campaign position in favor of 100 percent parity in farm product prices. Essentially, this means that farmers would be guaranteed prices in step with increases in the rest of the economy. Parity is an index of farmers' purchasing power now compared with the years 1910 to 1914. Under it, a unit of production, say a bushel or pound or bale, should buy as much as it did in the 1910-1914 period, with adjustments for technological gains. Phillips and the AAM contend that prices have fallen to 64 percent parity, the lowest point since the Great Depression.

It may be more accurate to say that the Agriculture Movement discovered Phillips, rather than the other way around. "When I read a newspaper story about his position on parity. I called him up and went to work for him," Earl Frazier, a Fauquier County farmer and Virginia AAM delegate, said in an interview.

"We're going to turn out 10 people for him at every mass meeting in the farm areas," Frazier said. That could be enough to guarantee delegate representation for Phillips in many rural counties to supplement those the candidate has otherwise garnered in a long and relatively well financed campaign.

Phillips, 48, has been in the Senate race longer than anyone else. He did not formally announce until last fall, but was actively laying the groundwork for his campaign more than a year before that. As early as Labour Day 1976 he was riding in an open car labeled only with his name in the Buena Vista holiday parade, a traditional western Virginia political event.

The "Who's that?" query the followed him along the parade route that day has been only slowly answered over the ensuing months as Phillips has labored to wedge his way in the statewide politics.

In this endeavor he has relied on a bag of campaign techniques not usually employed in contests for convention delegates.

He has publicized a toll-free line into his Northern Virginia headquarters to receive questions and offers of support.

He has staged half-hour, live quiz-the-candidate television shows in major cities.

As the centerpiece of his public campaign, he and his wife Barbara have spent a day working at each of about 30 jobs around the state. His tasks have ranged from barnacle scraper, to coal miner to teacher's aide and hers from hair dresser's assistant to gas station attendant.

It is not clearn that all of this has produced much for Phillips beyond a little publicity in the newspapers of the small towns where he has worked.

"In the end," said one campaign staff worker, "you have to ask yourself, 'Why Rufus? Why in this year when the Democrats are desperate for a winner would they turn to a guy who lost his last race for Fairfax Board of Supervisors."

Phillips served on the board from the Dransesville District from 1971 to 1975, then lost his seat by eight votes out of 15,000 cast to Republican John P. Shacochis.

Phillips believes his loss should not be weighed heavily. "There is no one in this race except Hunter Andrews who has not lost a political race before." Andrews, state senator from Hampton, has has not been opposed since he unseated an incumbent in 1963.

Phillips impressed many Democrats, last year when he hired Bill Ramjue, manager of Charles S. Robb's successful campaign for lieutenant governor in 1977, to manage his Senate race. Then he dismayed those same Democrats by firing Ramjue in a disagreement over campaign operations. "Ramjue was the best thing Rufus had going for him," one campaign staffer said, "and he fires him."

Phillips refuses to discuss the firing, saying "I don't want to say anything to hurt Bill.

phillips takes a somewhat distinctive approach to the role of a federal legislator in that he thinks senators should go beyond the task of legislating policy to take a greater part in program management.

"Oversight of the administration is an important function," he said in an interview. "I believe a senator should play a role in the implementation phase of government."

At another point, he said, "I'm not a traditional legislator. I don't believe in legislation as an end in itself. I'm interested in how these programs are managed."

His view of the job he seeks rests heavily on his won experience in the federal bureaucracy, especially in his last job as manager of community programs for the Agency for International Development in South Vietnam in 1963. It was on experience that left him with the abiding feeling that the bureaucracy, often out of a lack of candor, does not serve elected officials and the public well.

He often recalls in his campaigning how he told the late President Kennedy at a National Security Council meeting in 1963 that the United States was losing the war in Vietnam, a report that was contradicted by top Pentagon leaders present. The episode in chronicled in David Halberstam's "The Best and the Brighest," a book that Phillips carries with him on his campaign tours.

Phillips is one of several Democractic candidates relying heavily on his own money to finance his convention campaign. He said he has put about $125,000 of his own funds into the race, an amount ejual to about 25 percent of his net worth.

He recognizes the odds against him, but remains optimistic. "I'm not a front-runner," he said in the interview, "but I believe I'm coming up fast."