John A. Wilson has raised more than $500,000, cornered the market on endorsements and faces a little-known Democratic rival in the primary race for D.C. Council chairman. So why does he stand in the rain greeting potential voters, as he did one recent morning at the Van Ness Metro station?

Wilson, who eschews an umbrella, chalks it up to his competitive nature. "We'll be out here until we win it," Wilson said. "You should never take your voters or your opposition for granted."

In his first citywide campaign since an aborted bid for mayor in 1982, the onetime civil rights activist is running hard on a platform of expanding the council's power and prestige. This is a relatively novel idea in a city accustomed to strong executive leadership under Mayor Marion Barry, Wilson contends.

"A lot of people don't really understand the authority the council has," said Wilson, one of three remaining members of the original home rule council elected in 1974. "I want to use that authority, and I don't think it's been used to the maximum. I want to push it to the max."

Wilson's opponent in the Sept. 11 primary is Vincent Orange, 33, a lawyer and accountant and former employee of the D.C. Department of Finance and Revenue. With a small budget, Orange has mounted a spirited campaign attacking Wilson's stewardship of the Finance and Revenue Committee and noting that the city's finances deteriorated during his watch.

"Now is the time for voters to look at the background and expertise to help get the city out of its financial trouble," Orange said. "If John Wilson hasn't been able to do it in the past 16 years, why give him four more years? It's time for him to go."

As chairman of the Finance and Revenue Committee for 11 years, Wilson emerged as the council's leading voice on fiscal matters, repeatedly goading the body to thwart Barry's tax and budget plans in recent years.

Now Wilson, 46, viewed by many as one of the city's canniest politicians, is exploring other ways of augmenting the council's authority.

He wants to change the D.C. Charter to give the council power to alter Zoning Commission decisions, a move that would give the council unprecedented authority to respond to community concerns about excessive development in neighborhoods.

He intends to expand the council's oversight and investigation of the public education system, arguing that the council has done little more than issue checks to the D.C. Board of Education, without demanding accountability.

And Wilson would like to merge the Finance and Revenue Committee into the Committee of the Whole, which has jursidiction over the city's budget.

The resulting committee would have wide-ranging authority over the budget, the sale of bonds and taxes. With Wilson as its head, he potentially would be the most powerful council chairman in the 16 years of home rule.

"Whoever the new mayor is, under John's leadership the new council may turn out to be the policy director in the city," said council member Jim Nathanson (D-Ward 3). "I think the potential is there for the council to take charge."

Wilson, who is noted for his blunt and somewhat offbeat political rhetoric, was dogged during his short-lived mayoral campaign by criticism that he was too volatile a personality to lead the city. In recent years he has tried to moderate his public image. He still occasionally erupts during council meetings, and Orange has raised questions about Wilson's temper during the campaign.

Some longtime students of D.C. government question whether Wilson will have the patience to preside over 12 often feisty colleagues, who have shown no qualms about challenging other chairmen, including incumbent David A. Clarke.

Wilson says his temper won't be a problem. "I've wanted to be chairman of the council for a long time," he said. "It would be extremely foolish for me to blow it on some temper tantrum. This is a difficult time, and we're going to have to be cautious about the way we approach things."

Although Orange is given little chance of an upset, Wilson is taking no chances. He filled a campaign war chest second only to mayoral candidate John Ray and effectively foreclosed more serious competition from getting in the race.

Like Ray, Wilson has relied heavily on downtown business interests for contributions. Of the $474,881 raised through the middle of June, Wilson received $138,435 -- or 29 percent of his money -- from real estate developers, landlords and brokers. He also collected nearly $35,000 from parking executives and more than $73,000 from lawyers.

Wilson picked up a string of endorsements from a broad range of interest groups, from the Gertrude Stein Democratic Club and Metropolitan Area AFL-CIO to the Tenants Organization Political Action Committee and more than 50 ministers, including Bishops Smallwood Williams and Walter McCullough.

Perhaps most important, Wilson has assembled his first citywide political organization after 16 years of representing Ward 2 on the D.C. Council. He hired one of the city's most experienced campaign managers, former Barry campaign aide Phyllis Jones, and lined up prominent community activists in all eight wards of the city.

Campaign workers are stressing Wilson's record on health care, housing and other issues besides taxes and the city budget, Jones said.

The suspicion lingers in the political community that Wilson would like to be mayor one day, but Wilson emphatically disclaims that idea.

Pointing to the gravity of the city's financial crisis, Wilson said, "If I'm able to get us out of this situation, it is going to take every ounce of strength and energy that I have. {After that} I will be happy to go home."

In waging his uphill campaign, Orange tells audiences that he would bring fiscal responsibility to the city, hold the line on taxes and provide affordable housing and educational opportunities for the city's youth.

Orange and his supporters have plastered his distinctive signs, with orange lettering on a blue field, throughout the city. He has made frequent appearances at community forums, picnics and Metro stops and has bought some television spots.

"Everyone knows that Vincent Orange is running," Orange said.

Last January, Orange quit a $50,000-a-year job with the District government and took his $8,000 in retirement money to run for political office. During his three years with the city, Orange worked as a lawyer and manager for the District's Tax Amnesty Program, and was appointed acting chief of the District's Office of Real Property Tax Assessment Services Division.

Orange said he proved his financial prowess, saying that his division brought in more than $575 million while he was a supervisor.

While working for the District, Orange said, he closely observed Wilson.

"His methods are outmoded and that's why we're in the financial dumps," Orange said.

Orange said his opponent talks too much about raising taxes instead of thinking of ways to overcome the city's fiscal crisis.

"His only solution is to always raise taxes," Orange said. "Wilson brought us a $99 million tax increase last year," referring to Wilson's support of a tax package adopted by the council.

Now, Orange said, Wilson is talking about another round of tax increases, coupled with spending cuts, to deal with the city's looming deficit.

"Not once has he uttered that we ought to be out on the streets collecting money that is already owed to us," said Orange, noting that more than $200 million is owed the city in unpaid income and business taxes. "If we were able to collect that money, then we wouldn't need that tax increase."

Orange, who grew up in Oakland, lives with his schoolteacher wife and their two children in the Brookland neighborhood of Ward 5. In addition to his private practice, he works at The Washington Post on weekends as the security supervisor.

Orange, making his first bid for public office, has raised about $40,000 -- a small fraction of what Wilson has collected. But he remains confident, noting that he has been lucky so far. He won the lottery that placed his name first on the primary ballot.

"People are definitely ready for a change," he said.