When Clive L. DuVal 2d, the McLean gentleman-lawyer and Democratic Virginia state senator, was in charge of drawing new senatorial districts in 1981, he took care of everyone but himself.

DuVal gave away so many Democratic neighborhoods--to Democrats like Arlington Sen. Edward M. Holland on the east, Loudoun Sen. Charles L. Waddell on the west and Fairfax Sen. Adelard (Abe) L. Brault on the south--that his exasperated supporters told him he had pinned himself into a Republican corner of McLean and Great Falls that would never reelect him.

DuVal finally asked Brault if he would, please, take a couple of predominantly Republican precincts back into his district. "I told him I would not accept them," Brault recalls, "and I did not accept them."

If the 73-year-old Brault is the Jimmy Cagney of the Virginia Senate--short, tough and menacing--then the 70-year-old DuVal is its Jimmy Stewart, tall and soft-spoken and unfailingly good-humored. When Brault retires at the end of this year, DuVal will be in line to replace him as the leader of Northern Virginia's delegation--assuming he wins reelection this fall and his party maintains its majority in the delegation.

The region then will discover whether the patrician of the Senate, the Groton-and-Yale man with the Averell Harriman eyebrows, can bring home the Metro and education dollars the Washington suburbs want. Some in the 40-member Senate say that DuVal, like most Northern Virginians, is neither tough nor savvy enough to cut the deals and punish the renegades.

"When Clive wants your support, he'll say two things: 'Thank you,' and 'I wish you could help me on this,' " one senator said. "Abe would say, 'You'll have a bill sometime. Your turn will come.' "

Others say DuVal cannot be dismissed so easily. Majority Leader Hunter B. Andrews, who probably wields power with more skill and glee than any other senator, has befriended DuVal, and propelled him into the chairmanship of the Democratic Caucus. Andrews said DuVal radiates a special kind of influence.

"He is the gentleman, certainly," Andrews said. "In the Virginia legislature, that counts for a lot."

DuVal has had some victories, usually after introducing the same legislation every year for three or four years until he gets it through. His bills have strengthened clean water standards, protected the state's wetlands and allowed pharmacists to sell generic drugs in place of more expensive brand-name pills.

"The secret to legislative success in Virginia is courtesy, patience and persistence, and you'll usually get what you want," DuVal said. "You won't get it if you scream about it, and you won't get it if you're not willing to wait a long time."

In many ways DuVal is an odd choice for Virginia gentleman. A Manhattan-born liberal, he spent most of his life as a Rockefeller Republican. He came to Washington as an Eisenhower administration lawyer and turned to the Democrats in 1964, when Barry Goldwater was the Republican presidential nominee.

He also is the lord of Salona, a 55-acre, $1.2 million historic estate in the heart of McLean, but he rides a Greyhound bus to Richmond, stays on the wrong side of Main Street at the modest Downtowner Motor Inn and roams his property in Fairfax County gathering discarded aluminum cans he cashes in for $7 or $8 every few months.

Like many of his well-heeled McLean neighbors, DuVal first entered local politics to fight the Wild West, scandal-ridden zoning policies of the county board in the 1960s. When a developer won approval to build two 17-story apartment buildings on the Potomac-front Merrywood estate, DuVal went to court on behalf of a citizens' association, spotlighting so many facts embarrassing to the courthouse crowd that the project, with the help of then-Interior Secretary and DuVal neighbor Stewart Udall, was ultimately defeated.

DuVal has been representing the interests of the people, as he sees them, ever since, fighting for environmental and consumer legislation and against pensions for unscrupulous judges. He frequently appears before the State Corporation Commission as a self-appointed and unpaid people's representative opposing utility rate hikes in Virginia. "I know it sounds square, but I believe government is meant to do something for the people, not the other way around," he says.

DuVal was first elected to the House of Delegates in 1965, the year Brault became a senator, and has served in the General Assembly ever since, the only Democrat who survived a county-wide Republican sweep in 1969. When he ran for the U.S. Senate nomination in 1970 (one of his three unsuccessful bids for Congress) DuVal lost by 701 votes out of 135,000 cast in a three-way race--and then waived his right to a runoff and signed on as treasurer for his erstwhile opponent's campaign.

Despite his largely Republican district--even his neighbor, Democratic Gov. Charles S. Robb, could not carry it in his 1981 campaign--DuVal is given a good chance of beating his likely opponent this year, former legislative candidate Clairborne B. (Buck) Morton of McLean.

"Only Clive or a person like Clive could win that district," said Fairfax Democratic Party chairman Dottie P. Schick. "He is one of those people . . . he belongs."

In Richmond, however, DuVal has been more of an outsider. In the early days the House speaker assigned him, along with Republicans and a few liberals, to the Public Institutions Committee, which had never met. Many of his proposals--for an elected corporations commission, for a ban on disposable bottles, for tougher air pollution laws--were killed year after year.

He has never been granted a committee chairmanship, and though he sits on the Finance Committee, he is given little more than the privilege of routinely approving the budget proposals that the committee's "Secret Seven"--the members of a powerful subcommittee--work out each year behind closed doors.

"He's an eastern establishment liberal in a southern conservative environment, and they clash," said Fairfax Republican Del. Vincent F. Callahan Jr., the House minority leader. "They shoot him down all the time, but he's such a nice guy they do it nicely, without animosity."

DuVal responds courteously, surveying the wreckage of his legislative program with tolerant equanimity. Where Brault will jump to his feet, sucking in his breath with an angry rattlesnake rasp, DuVal listens attentively and explains his bills calmly, as if he really believed that only reason and merit count in the legislative process.

"It took me years to realize that it's not a ploy, it's not a ruse, he really thinks that way," said Pixie Bell, a Democratic activist in Fairfax County and DuVal's campaign manager. "He thinks that way even when you would like to clobber him over the head and make him think like a politician."