Walter E. Fauntroy, who took the biggest political gamble in his career to run for D.C. mayor, suffered a crushing defeat last night, ending nearly 20 years as the city's first delegate to Congress with the support of only 7 percent of the voters in the Democratic primary.

At the Black Entertainment Television studios of campaign manager Robert Johnson before about 150 supporters, Fauntroy made a concession speech that took the reflective tone of a sermon.

"I am disappointed, of course, that I did not win," he said, "and that I will not have the opportunity to personally implement solutions to some of the most serious problems facing any city in this nation. But it appears at least one part of my mission did succeed. That was to get fresh ideas."

The man who finished fifth out of five had spent most of the primary day cruising from precinct to precinct in a three-car caravan, seemingly oblivious to projections that he would not only lose -- but lose big.

He popped out of his car at one stop, smiled sublimely at campaign workers and cited chapter and verse to a reporter.

"Consider the lilies of the field, how they grow," he said, ever the pastor of New Bethel Baptist Church. "O ye of little faith."

Fauntroy's decision to run for mayor, made suddenly while Marion Barry was out of town in addiction treatment after his arrest on drug charges, surprised many D.C. residents. It also triggered a scramble as Betty Ann Kane (D-At Large) vacated her council seat to run for delegate, and politicians from the council to advisory neighborhood commissions followed suit in quest of higher offices.

It is no secret that Fauntroy's family was upset by his decision and that some of his closest advisers counseled him against it.

Johnson, the cable television executive, who left the Barry camp to manage Fauntroy's campaign, said yesterday that Fauntroy failed because his forces neglected "to take some soundings of the local political waters" early enough.

As a result, Johnson said, they were dogged by questions such as, "Walter, why are you doing this? Who fits into your equation?"

Fauntroy raised slightly more than $300,000, less than a third of John Ray's war chest but nearly $75,000 ahead of winner Sharon Pratt Dixon.

As the Dixon victory unfolded, Johnson credited Fauntroy with laying the groundwork for her stunning upset. "It's because Walter Fauntroy did the work," he said. "Walter Fauntroy brought out the fact that the amount of money given to Ray was detrimental to the people of Washington."

But many voters also appeared confused and dismayed by Fauntroy's campaign strategy. Some found his branding of Ray as "the great white hope" distasteful and out of keeping with the kind-hearted and fair man they knew him to be. Others found his performance on the stump so awkward as to be humorous.

"Walter wanted to deal with things in specific ways with papers and plans," Johnson said. The contest was one of "how quick you were with your tongue and 30-second sound bites, and that's not Walter's forte."

At one forum, Fauntroy referred repeatedly to his 32-page "Plan for Solving Our Budget and Management Crisis," eliciting some giggles from the audience.

The former lieutenant of the Rev. Martin Luther King Jr., engineer of D.C. home rule and graduate of Yale Divinity School was reduced to pleading: "Don't laugh at my plan."

Randall Robinson, head of the lobbying group TransAfrica, said, "It is personally very saddening to me to think that Walter is vastly underappreciated for his contributions over the last 20 years. He is one of the most decent and courageous public figures I have ever worked with. We couldn't have had sanctions against South Africa without Walter Fauntroy."

After the first feeble results were in last night, campaign worker Don Hudson, who had worked the day in a precinct in upper Northwest, said he felt "really hurt. The machine fell apart this election. And I suppose people felt that Fauntroy was part of the machine."

"He was never taken seriously," said one acquaintance who asked not to be identified.

Fauntroy said yesterday that his decision to run for mayor was a "very spiritual one, which nobody would understand."

He said he has given no thought to what he will do next. Johnson said he is sure to get a pension, as well as support from his church.

"I will continue to serve people in a yet to be determined way," Fauntroy told his supporters last night. "Don't worry about me. I am upbeat and I am confident."