Supply-side economics may be the talk of Capitol Hill, but will it work in Loudoun County?

In a political version of double-entry accounting, Steven Stockman, the younger brother of federal budget director David Stockman, is hoping to use low-tax slogans and high name recognition to unseat a longtime Democratic supervisor this fall.

"It sounds funny, but the name recognition is my biggest problem," Stockman says, meaning he doesn't get enough. "But we're going to take care of that. I'm having my first fund-raiser in September, featuring as guest of honor--guess who--Dave Stockman."

Although skirmishing for Virginia's November elections typically begins after Labor Day, Stockman already has begun what is shaping up as the Battle of the Budgets.

"Supply side, yeah," says Stockman, a $42,000-a-year international affairs analyst for the Department of Energy who moved to Loudoun's Sugarland Run area from Washington four years ago. "It's free market, really," he says, going on to quote "Laffer and Kemp and those guys," the gurus of the supply-side movement.

But Stockman, a Republican running as an independent (as required of federal employes by the Hatch Act), is an equal oppportunity quoter.

"I'm running as 'the taxpayers' friend,' " Stockman says. "I just think people can spend their money better than the supervisors can spend it for them . . . As Thomas Jefferson said: 'That government governs best which governs least.' "

Stockman, a 33-year-old political novice who has a law degree and a real estate license, is challenging Democrat Carl Henrickson, 34, for the Broad Run district seat on the County Board that Henrickson has held since 1974.

The Democrat, who operates computer sales and typesetting businesses, says he is a proven ally of Loudoun taxpayers. "People here want good, efficient, quality local government, and I think that's what we've got," he says. "In that sense I am the taxpayers' friend."

The district where Stockman has chosen to seek his political spurs is the suburban frontier of Washington's westward expansion. Like a border boomtown along the Loudoun-Fairfax county line, wedged between the Potomac River and Rte. 7, the district covers only about 17 square miles, one-thirtieth of the county, but has more than one-eighth of its population.

"Probably 95 percent of the voters are under 50," Stockman guesses. "In probably half the couples, they both work. They live in small, not elaborate but nice homes in a planned community . . . It's basically the American dream."

Stockman thinks there's a snake in the grass. Wielding a sheaf of graphs and news releases showing a 178 percent increase over the past eight years in the county operating budget, and a virtual elimination of capital improvement funds, Stockman has accused the Board of Supervisors of "robbing Peter to pay Paul!"

"They've shifted it all to the county administration to keep the taxpayers from complaining," he says. "The only way to get more funds to build in the future will be to raise property taxes."

Henrickson, who spent three years as head of the county board before becoming chairman of the Washington Metropolitan Council of Governments, says Stockman has made a major apples-and-oranges error.

"To suggest we've been paying for a growing county government out of bonds is just wrong," says Henrickson. "We never used general tax revenues to construct." The building boom of the 1970s, according to Henrickson, was financed by the $28 million bond issue of 1972 and another, smaller issue in 1978.

Henrickson acknowledges that Stockman's name could give him an advantage in raising funds, but says he is counting on his record on the board to be his major campaign asset.

Although Stockman often seems self-conscious, and refers more than once to his opponent's popularity and good looks, he maintains a disarming humor about his own candidacy.

"Here I am, dying for name recognition, and look what happened to the headline," he says, holding up a reprint of a Loudoun Easterner story that appears to have lost the top line. "The name is missing."

And Stockman, who moved to Washington in 1971 at the urging of his brother, then a congressional aide, speaks of having chosen to print a plain brochure because "two-color costs money."

"I have what I call a 'bare-bones budget,' a 'make-do budget' and an 'I wish' budget," Stockman says. "Four hundred dollars . . . $750 . . . $1,200."

And he readily turns political jokes back on himself. "When I was approached about running, I reminded my wife of what Will Rogers said: 'Once a man runs for public office, he's no good for honest work.' She said, 'Go ahead and run--but you better win.' "