WE WOULDN'T ordinarily indicate a preference in a state primary, but we are delighted to make a single exception in the Virginia's Democratic primary to be held next Tuesday. Del. Ira Lechner of Arlington, an exceptional candidate, is running for lieutenant governor, a post of importance mostly as a stepping stone to bigger things. He has a record of enlightened and effective service in the General Assembly and the potential of helping turn the state's still-riven Democratic Party into a workable instrument of government. His opponents, Richard Reynolds, scion of a Virginia political family, and Charles Robb, scion-in-law of a national political family, are pleasant and promising men who are, you might say, still working their passage onto the state political scene, while Mr. Lechner, by comparison, has long since arrived.

We address the race for the gubernatorial nomination with less certainty and a good deal more reluctance to depart from a general rule about expressing primary preferences. This contest indicates just how far the party still must go to shed the debilitating legacy of the Byrd machine. Former Lt. Gov. Henry Howell, a valiant but tired self-styled populist making his third try for the office, hopes against long odds to muster the state's political left and center to beat the Republican nominee, John Dalton, in the fall. Former state Attorney General Andrew Miller, a competent political operator of several stripes, is trying against only slightly shorter odds to unite all of the fiefdoms and factions of the state party. Voters must weigh not only the differences between their strategies.

We are equally unmoved to express a ringing preference in the third statewide race, for attorney general - also a post important as a stepping stone. The field includes two progressive Northern Virginians, Del. John Melnick, who is experienced, and John Schell, who is not, plus Del. Edward Lane of Richmomd, a veteran legislator who earlier considered running for governor as a Republican, and Del. Erwin Solomon of Bath County, who is to us an unknown.