Several weeks ago, a photocopy of a newspaper article arrived in my office, courtesy of a veteran political correspondent who has retired to the gentler climes of Culpeper, Va. Sexism, he had noted in the margin, is alive and well in Virginia.

Indeed, it is.

The article was an account of a fund-raiser held in Charlottesville for W.R. (Buster) O'Brien, the Republican candidate for state attorney general. O'Brien is a lawyer who has been married 11 years and is the father of three. His opponent is Democrat Mary Sue Terry, also a lawyer and veteran legislator, and the first woman to be nominated by a major party for statewide office.

She is single.

According to the article, Republican state Del. George P. Beard of Culpeper, introduced O'Brien by saying he "knows more about criminal law in his little finger than his opponent knows in all five of her ringless fingers."

The article went into my "Yech" file, which is reserved for minor atrocities I wish had not happened. But it did happen and word got around, and, according to a story in Sunday's Washington Post, Republicans were embarrassed, as well they should be. Democrats, according to The Post story, complained that Republicans are using "family issues" to make "unfair and often crude charges against their candidates, especially Terry."

GOP spokesman Don Harrison said family issues are "a way of saying what your root values are."

On a recent trip into Virginia on behalf of Republican gubernatorial candidate Wyatt Durrette, President Reagan made much of the "family issue," saying that he often thinks "the real heroes of today are the parents . . . . " Durrette is the father of seven, including a 6-week-old baby boy, who apparently bounced right out of the womb onto the campaign platform.

Families have traditionally been one of those subliminal campaign issues that are supposed to tell you something about a candidate's character. Divorce, for example, was once thought to be a crippling character defect for a politician.

A person's family is also a sword that can cut both ways.

Corporations once judged men with families to be more stable and reliable. Other corporate cultures went through a phase of doting on single men who could put in the 14-hour days. And women can still tell you stories of not getting jobs because employers ask them who is going to take care of their children.

Family concerns may say something about one's "root values," but they can also say something about one's ability to do a job. It's all a matter of perspective. Turning the tables, for a moment, we can find that Mary Sue Terry has a lot going for her.

She doesn't have any children to distract her. She can put in the 14-hour days that can make the state attorney general's office great. She won't have to worry about child care, or helping kids with homework. No one is going to wake her up in the middle of the night with a terrible earache. She won't be distracted from her work by the occasional strife that strikes every marriage.

I'm not worried about Mary Sue Terry and her ringless fingers.

I'm worried about Wyatt Durrette and his seven kids.

Ronald Reagan is right: being a parent today is heroic and being the parent of seven is about as heroic as one can get. But does Durrette, given the job he has at home, have the time to be governor? Is he going to be fit to serve?

We are talking here of a man who is the father of a 6-week-old baby. He isn't going to get a decent night's sleep for months. His oldest child is 22, which means that Mrs. Durrette isn't 25 anymore, and may take a little longer to get back to full speed after this last baby. With that many children, will she have the time and stamina to be first lady of Virginia?

This is a couple that really has their hands full. How can they be available for evening functions? They're going to be home helping the kids with homework and getting them to bed.

Why, family obligations have even hampered O'Brien, who has only three children. Asked recently why his campaign got off to a slow start, an O'Brien campaign aide explained that the candidate has a full-time law practice and that "he's had a family, different obligations. She's obviously a single-minded woman."

Perhaps both gentlemen ought to wait until their children are grown and they are free to devote themselves to public service. Virginians like root values, but it wouldn't do to have their top officials constantly distracted by family responsibilities.

All of which is to illustrate that when a sword cuts both ways, sometimes it's better not to use it at all.