Incumbents Outspending Challengers : Election: Candidates hoping to unseat four council members lagging in campaign spending by margins exceeding 10-to-1.

Flexing the fund-raising muscle of incumbency, the San Diego City Council members seeking reelection in next month’s primaries are heavily outspending their challengers, most by margins exceeding 10-to-1.

With less than seven weeks remaining before the Sept. 17 primary in the council’s four even-numbered districts, the four incumbents--Ron Roberts, Wes Pratt, Bruce Henderson and Bob Filner--have already surpassed or are approaching the $100,000 mark in their campaigns, a threshold that their opponents seem unlikely to cross.

The top fund-raiser among the four incumbents--each of whom is seeking reelection to a second four-year term--is 8th District Councilman Filner, who had received contributions totaling $130,305 and had spent $118,769 as of June 30, according to campaign finance reports filed Wednesday with the city clerk’s office.

In contrast, Filner’s major challenger, long-time San Ysidro community leader Andrea Skorepa, had raised only $19,426 as of that date, with $5,000 of that being a personal loan. Skorepa has spent $16,825, about one-seventh as much as Filner, the reports show.

Filner’s other opponent, South Bay activist and political unknown Lincoln Pickard, had not filed his report as of late Wednesday. However, Pickard said in an interview that he has raised and spent less than $1,500, with about half of that being his own money.

That same pattern can also be seen in the other district-only races, with well-funded incumbents financially eclipsing their opponents, adding yet another hurdle to the challengers’ already uphill campaigns.

Historically, the relative size of candidates’ campaign treasuries is a significant indicator of the races’ likely outcome, with those who draw the most contributions also generally being victorious.

In the 6th District, Councilman Henderson had raised $116,365, nearly two-thirds of that last year. During the January-to-June period covered in Wednesday’s report, Henderson raised $33,881, still substantially more than the $6,836 contribution total of his sole opponent, Salk Institute researcher Valerie Stallings.

Henderson has spent $71,746, including $27,826 during the past six months, while Stallings’ expenditures total $4,174.

A similarly lopsided financial picture emerges in the 2nd District, where Councilman Roberts’ reelection campaign is widely viewed in political circles as a prelude to a 1992 mayoral campaign.

As of June 30, Roberts had raised $108,071 and spent $114,168, his finance report shows. Combined with funds raised earlier, Roberts, who, like the other incumbents, began raising money for this year’s race in 1990, reported a $28,192 balance in his campaign treasury.

Roberts’ opponents, retired teacher Richard Grosch and Loch David Crane, a magician and frequent long-shot candidate, received only a fraction as much in contributions in their respective campaigns. Grosch said late Wednesday that he has raised $7,209, while Crane typically spends less than $1,000 in his almost-annual campaigns.

In the 4th District race, Councilman Pratt has raised $93,000 and spent $63,876. The report of his only opponent, the Rev. George Stevens, whom Pratt defeated in 1987, was not available.