Just before he arrived at the scene of his debate with Rep. Paul Trible (R-Va), Democrat Law Puller switched places with an aide and took the wheel of his Jeep Comanche.

"Every candidate for Congress has a driver," explained the aide, Tom Rastetter, "but Lew is the only one who has to be driving when he arrives at a meeting."

It's part of an effort to prove to the voters of Virgina's 1st Congressional District that Puller, who lost both legs and part of both hands in Vietnam, is mobile enough to go to Washington as their congressman.

Puller scooted out of the Jeep and pushed himself to the motel's banquet room-another rule is that no one is to push the wheelchair for him-where the scene could have been out of one of those postwar movies.

There is Puller, the war hero, seeking to catch up for lost time that he spent on the battlefield and recuperating (two years at the VA hospital in Philadephia) against an opponent who got the jump on him back home.

Trible, a freeman House member who is the first Republican ever to represent the district in Congress, suggests that his opponent is exploiting his tragedy at Trible's expense.

"My opponent places great emphasis on his father's name and his own tragic experience in Vietnam," is how Trible puts it.

An example of that emphasis is found in an article Puller wrote for the October issue of Tidewater Life magazine.

It begins: "Ten years ago I made a commitment to our country, as my father. Gen. Lewis B. (Chesty) Puller had done before me. (His late father was the most decorated marine in U.S. history) I volunteered to serve as a Marine infantry officer in Vietnam at a time when many of my peers were finding ways to avoid service or located safe billet. My commitment cost me both legs and part of both arms."

His sacrifice also is the theme of his major advertising effort, a 12-page newspaper supplement headed "Lew Puller is Fighting For His Country. Again." It was distributed, at a cost of $9,000, by a dozen newspapers that circulate in district, which sprawls from just south of Fredericksburg on both sides of the Chesapeake Bay to the Hampton Roads area.

Puller's strident literature contrasts with his modest and somewhat shy personal demeanor. Puller says he doesn't talk much about his handicap, although he is quick to admit such talk isn't necessary.

While campaigning earlier this month with Lt. Gov. Charles S. Robb on the sparsely populated Eastern Shore, Puller was approached by a middle-age man in overalls and hard hat who shock his hand and then reached in his wallet and gave the candidate a dollar. Puller gave it back with a smile.

"I hate that," he said as he wheeled away. "It happens all the time. You're wearing a $200 suit and they think you're panhandling."

Trible, who at 32 is a year younger than Puller, was classified 4-F because of a bad left arm. He resents the implication in Puller's literature that he might have "avoided service."

But Trible's campaign hasn't been marked with subtlety either.

In that same issue of Tidewater Life, Trible managed to give the impression that he was the first member of Congress ever to ask his constituents their opinion, or conduct town meetings or hold office hours back home.

Trible, whose tall, blond appearance makes him look like the award-winning Jaycee he is, is at ease talking about his accomplishments-he includes notice of private Bible study at the Capitol on his press releases-and those of his wife Rosemary.

Mrs. Trible, a former Junior Miss in her native Arkansas and a one-time Richmond television talk-show hostess ("Rosemary's Guest Book") is "well informed . . .and pretty too," her husband is fond of saying.

In the debate that followed, Puller attacked Trible's conservative record. In recent days, he has focused on what he calls "Tribe's nine worst votes on issues important to blacks and lower-income families."

But there were few of either of those groups at the Jaycee meeting, and it was that Trible's votes against Humphrey-Hawkins full employment legal aid and child nutrition were of less interest than his support of the Kemp-Roth tax cut plan, a differential minimum wage for youth and his vote against funding the CETA program.

More importantly, Trible may have asured his reelection nearly two years ago, when he arrived in Washington as the only new Republican to be elected from the South. He persuaded the GOP leadership to give him aspot on the Armed Services Committee, even though ther alays three other Virginians on it.

As a member of the committee. Trible has supported military and defense spending issues critical to a district that has eight military bases, two NASA installations and the Newport News Shipbuilding and Dry Dock Corp, with 24,000 civilian employes, the largest private employer in the Southeastern United States.

Trible is taking credit-and many voters in this part of the state say he deserves it-for halting a potential $2 billion contract to the Philadelphia Navy Yard to overhaul the USS Saratoga and three other aircraft carriers.

Puller is attempting to blame Trible for almost allowing the huge contract to get away, "but nobody believes that," Trible said.

Nonetheless, Trible is "running scared," outspending Puller nearly 2 to 1 (with contributions totaling $186,000 to Puller's $111,000) despite a poll in last Sunday's Newport News Daily Press that showed the incumbent with a 70-to-25 percent lead.

"I remember two years ago a poll showed I was behind by 24 percent in mid-September," said Trible, noting that he went on to win "by the skin of my teeth (about 1,600 votes).

"This is one young man who feels America's greatest years still lie ahead," Trible said," and I want to do my part."