President Carter's oldest son, Jack, ended a three-day "Death Sweep For Miller" here today after a blitz of Virginia on behalf of his friend, gubernatorial candidate Henry E. Howell.

If politics are at least distantly related to the circus, Jack Carter proved to be one of the class acts of this campaign, which ends with next Tuesday's Democratic primary.

In a political season that has seen a former First Lady, Lady Bird Johnson, planting trees and shaking hands on behalf of her son-in-law; movie star Elizabeth Taylor blushing and gushing all over Virginia on behalf of the Republicans; an attorney general candidate traveling around in a camper calling voters on his CB radio, and Howell's rival Andrew P. Miller planning a whistle-stop tour on an antique train this weekend, the 29-year-old President's son was clearly a draw.

Carter's day began officially with a press conference at Howell's Hampton headquarters, formerly the Jimmy Carter campaign headquarters. Standing before a half-dozen reporters, two television cameras and a typically eclectic crowd of about 30 Howell supporters (including three nuns). Carter said he was in Virginia as a friend of Howell and not as an emissary of his father.

He said that Miller "was really more of a Republican, philosophy wise," because he did not represent the interests of the "disenfranchised, the poor and the working man," as he asserted that his friend Howell does.

His first impression of Miller was tempered by an unpleasant first encounter in Galax last year, he said, in response to a question. At the time Carter was seeking Miller's support as a convention delegate for his father.

"I went up and shook his hand and asked for his support," Carter said. He jumped all over me about something I had nothing to do with in front of several people." Earlier, Carter has said "Howell worked for us (during the campaign) and Miller didn't."

Miller aide Steve Fleming said in response to all questions about Carter's visit and comments: "It's a beautiful time to travel across Virginia and we're glad he's here to enjoy June with us. But we think this political mission will not succeed.By the way, who's paying for the Secret Service?"

Carter, who is in the grain eleavtor business, drove from his home in Calhoun, Ga., Monday morning to Abingdon, Va. He was met there by two Howell supporters to accompany him and four Secret Service agents through Roanoke, Danville, Suffolk and small towns in between. Carter said the Secret Service pays for all ground transportation, but he pays if they fly.

The visit was deliberately not coordinated with the Howell campaign staff, which was besieged with inquiries from reporters wanting to know where Carter was and why. "I don't like to be scheduled," Carter said.

Carter came, as Howell would have put it, to witness for the former lieutenanant governor's character. "A mans' character is what you really have to know and it's a very, very difficult thing to put across in the news media. I think I'm informing the public when I say this is a great guy. I know him."

Although much of his time was spent visiting small town nespapers and radio stations or holding press conferences, Carter also stopped to solicit people on the street, in shopping centers, and at a plant gate in Danville. "Hi, I'm Jack Carter from Georgia and Henry Howell is a good friend of mine," he would say, handing the person a brochure. Often the person did not recognize him as the President's son.

"That was the President's son?" said a man at a Norfolk shopping center." "He just said he was Jack Carter from Georgia, so I said, 'Hi, I'm Al Sellers from Virginia Beach.'"

Meanwhile, Howell charged today that Miller stood silent in the face of a possibly illegal $40-million Virginia Electric and Power Co. surcharge imposed two years ago on Virginia consumers.

"I don't know where my family watchdog was," Howell said of the former attorney general. "He was attorney general then, but they got in the store and out with $40 million, and the watchdog didn't bark once.

"Howell, who spoke during a blitz tour of key country stores in rural Central Virginia, said the surcharge was imposed retroactively by Vepco with no public hearing in late 1975 to cover higher fuel costs duing June, July, August and September of that year.

"It was only four months but it was $40 million," Howell said. "That's almost as much as the Brinks robbery."

Howell said he has potitioned the State Corporation Commission, Virginia's utility regulatory agency, for a hearing on the legality of the surcharge, which he said has been declared illegal in other states.

He said the $40-million surcharge had been applied by Vepco on top of the automatic fuel adjustment clause ("that's piling evil on evil"), which automatically raises residential electric bills to cover the increasing costs of generating fuel.

Howell has made removal of the adjustment clause a keystone of his gubernatorial campaign.

Howell spent today on the backroads of Caroline, Stafford and Spotsylvania counties, storming crossroads like Post Oak, Mud Tavern and Guinea, slapping posters into stores he said thousands of rural voters will visit before election day.

While his Winnebago trailer's sound system played "Cuddle Up and Love Me One More Time," the three-time candidate for governor swept into the E. D. Finney & Daughter Grocery at Snell.

While the staff taped a Howell poster on the window next to a sign advertising "Live Canadian nightcrawlers," the candidate gladhanded Finney, 78, and his daughter, Genevieve, before a display of snuff cans, fishooks and chewing tobacco.

"Talk about me," Howell told the grizzled old man. "Your customers know you better than they know me." "That's right,' murmured Finney.