By all accounts, the annual Democratic barbecue at Milton Alexander's Northern Virginia home is a grand affair -- a quarter-center-long tradition that draws an array of state and local party leaders.

In an era dominated by slick political image makers and scientific public opinion surveys, the barbecue's ambience is a throwback to the down-home, backslapping, southern-style campaigning that once was the life-blood of Virginia politics.

That tradition of old-fashioned, good-old-boy loyalities, some Alexander critics say, may be behind the 71-year-old Alexander's appointment four years ago as Fairfax County's chief magistrate.

It also may play a role, they contend, in Alexander's reappointment last month to a second four-year term under an unusual administrative structure that Virginia officials are now trying to change.

A proposed state takeover of the 37 full- and part-time magistrates who work for Alexander in Fairfax has consistently been opposed by the county's Board of Supervisors, whose most senior member -- Alexander's son Joseph -- is a regular at the yearly barbecue an a strong foe of the takeover.

At the request of Milton Alexander's office, acting County Executive J. Hamilton Lambert is scheduled to appear before the board today to ask the supervisors to go on record as opposing the state's proposed reorganization -- a move that Lambert says would result in a cutback of services.

Supervisor Alexander said his opposition to state control has nothing to do with his father. "It's a matter of serving the citizens," he said. "This would be my position regardless" of who was chief magistrate.

Both Milton Alexander and the Official who appointed him, Chief Circuit Court Judge Barbard F. Jennings, denied that politics had anything to do with Alexander's selection as chief magistrate in 1976 at the age of 68.

"I didn't get my job through politics," Alexander said, adding that he has been politically inactive for several years. As for the barbecue: "I just let [the local Democratic Party] use the place. I have no connection with it at all."

"He was the best one available at thetime," Jennings said, adding that Alexander has done "an excellent job."

Magistrates in Virginia issue arrest warrants, set bail for criminal defendants and collect traffic fines.

Besides Fairfax, a handful of other localities remain outside the state system, including Arlington, Alexandria, Richmond, Fairfax City and Falls Church.

In constrast to Fairfax, the Arlington County Board has recently asked the state to take over its magistrate system, according to Arlington County manager W. Vernon Ford.

Ford said Arlington estimates it can save $100,000 a year by having the state take control. "All contributions from the state are gratefully accepted," Ford said.

The older Alexander's political roots stretch back to his support of powerful, old-line Virginia politicians such as the late Rep. Howard Smith and the late Sen. Harry F. Byrd Sr., whose once powerful organization dispensed patronage jobs in courthouses throughout the state.

"He's a conservative, loyal Democrat," one county officeholder said of the senior Alexander.

"He was a political appointee," said a magistrate who works under him. Some magistrates also complain that Alexander has ab abbrasive, inflexible personality.

"He doesn't give an inch," said one magistrate, who asked not to be indentified.

Alexander dismisses the criticism as the comments of a few disgruntled employes. "When I came here," he said, "this organization was run pretty loosely. Somebody had to be put it into a businesslike, efficient operation. He makes $21,370 a year.

An examination of Alexander's appointment and the Fairfax magistrate system, however, revealed that:

Although the county finances the entire magistrates budget, more than $500,000 a year, county officials have no direct administrative control over the magistrate operation. One top county official called it an administrative "hodgepodge." Magistrates are not covered by county civil service regulations or other personnel rules.

Although the mandatory retirement age for state and county employes is 70, Alexander, 71, is not affected by those rules. He can remain on the job as long as he is able -- longer than even the official who appointed him, Judge Jennings. The mandatory retirement age for judges is also 70.

The county could save more than $300,000 a year if the magistrates were placed under state control. Milton Alxander said the state would reduce the number of magistrates and force the county to close several of the eight magistrate substations scattered throughout Fairfax. "It doesn't make any difference to me," he said. "I'm looking at the overall picture for the county."

But a state official said a state takeover would not necessarily mean such cutbacks. The state, he said, "is just as much interested in having good service for the public as anybody in Fairfax."

Both Alexanders said they don't get involved in each other's public jobs. "I don't have to look out for him," said Supervisor Alexander, adding that his father's appointment came as "a complete surprise to me."

But on at least one occasion Supervisor Alexander used his position to intercede for his father.

During a 1977 meeting of the board's subcommittee on personnel, Supervisor Alexander, a member of the panel, complained that county officials were not cooperating enough wit his father, according to a confidential memo authored by then-county personnel director Dale E. Friesz. c

In his memo, Friesz said the county staff had advised the senior Alexander to take less drastic disciplinary actions.

Friesz expressed concern that Supervisor Alexander might have misunderstood his actions. "I am concerned that Supervisor Alexander appears to believe we are not acting in a supportive manner to the Violations Bureau director [a post also held by chief magistrate Alexander]," the Friesz memo says.

The senior Alexander said he did not ask his son to speak for him.

Supervisor Alexander said that as a member of the committee he has a right to partiipate in its proceedings.

"It was brought up by the staff, and I responded to it," he said. "I feel I was looking out for proper personnel policies."

Controversy about Milton Alexander also extends to a lawsuit brought by former magistrate Preston C. Thomas, who is asking $240,000 in a dispute over Thmomas' sick leave. The trial is scheduled for April 1.

According to Thomas' suit, Alexander told fellow magistrates "that he had influential connections with the county . . . [and] that state laws were made in Richmond and he was not concerned about the impact of those laws in Fairfax."

Alexander denies making any such statements.

In defense of Alexander's appointment, Judge Jennings pointed out that Alexander had once been president of the state association for magistrates and that he was "well respected" in the field.

Alexander had been an elected justice of the peace since 1953 and became a part-time magistrate when the county abolished its justice of the peace system in 1972.

Alexander's main occupation had been as an electrical contractor and consultant as well as being part owner of a hardware store he and his son had in Franconia, jobs he no longer holds.

In his present job as chief magistrate, Alexander keeps a low profile, rarely leaving his modest office in the basement of the county jail building.

"I don't need no picture in the newspaper," he said recently when asked to pose for a photographer. "I'm used to operating behind the scenes, so to speak."