Today Virginia's outgoing Democratic governor, Chuck Robb, will probably accomplish something that many more celebrated outgoing governors -- Ronald Reagan of California and Nelson Rockefeller of New York among them -- have tried and failed to do. In Virginia, Chuck Robb leaves as his legacy a record and a political environment that make likely the election of his party's nominee to succeed him. Virginia, its politics fundamentally changed by the Robb Revolution, looks determined to elect Democrat Gerald Baliles governor.

A Virginia revolution of any kind was, until quite recently, a contradiction in terms like "mine safety" or "cheerleading scholarship." Politically, most of Virginia and all of Richmond have been a hotbed of social rest.

Two centuries ago, the commonwealth of Virginia was extraordinarily blessed in its leadership, and our young country was the beneficiary. It was Thomas Jefferson who gave our nation its citizenship papers and who also, along with George Washington, James Madison and Patrick Henry, Virginians all, favored the emancipation of slaves. For most of the next 200 years, Virginia elevated political mediocrity to an art form, and fought tooth and toenail to maintain racial inequality.

Virginia and national Democrat Major Reynolds, who had never been an ardent admirer of Robb (to whom he lost a 1977 primary) credits the governor with "changing the political atmosphere of the state." Through four years of successful leadership, Robb has been able, according to Reynolds, "to kill all the political bogeymen."

Those "bogeymen" were the fears aroused by the political ruling class, which warned that if "those people" (read women, blacks, outsiders who were not the Right People) were somehow to gain power, the pillaging of the civic temple and the raiding of the public treasury would inevitably follow. Through the quality of Robb's stewardship and the distinction of Robb's appointments, that myth has been routed. As the first member of his party since 1966 to win a Virginia race for governor or senator, Robb, for a whole generation of the state's voters, became the only standard for Democratic performance in public office.

So positive has been public reaction to that performance that Democratic candidates for lieutenant governor and attorney general, respectively a black man and a white woman, are given an even chance to become the first in each category to win Virginia statewide office.

How impressive is all of this? Well, consider this: Ronald Reagan's Sacramento successor was Democrat Jerry Brown, who neither endorsed the same causes nor inhabited the same cosmos as Mr. Reagan. And since Rocky put Venezuela in a blind trust and left Albany to become Jerry Ford's vice president, New York Democrats have yet to lose a governor's race.

National Democrats, impressed by the Virginia transformation, are mostly admiring of what Robb has done but baffled by how he has done it. Some speak of his "daring," others of his presence and consistency.

Whatever the answer, Robb has successfully become in Virginia in 1985 a "valence issue." There are two kinds of political issues: position and valence. Position issues are those such as the Equal Rights Amendment and the Panama Canal Treaty, on which there are two opposing sides. Valence issues are those issues, such as handling unemployment or fighting crime, on which there are not two sides but where one candidate or one party is often seen as better than the other. So popular is Robb in the state that the Republican campaign identifies one of its chief spokesmen, presumably to give him credibility, as chairman of a Robb economic group.

In the words of Democratic strategist David Doak, who managed Robb's 1981 campaign and holds a leadership role in this year's Baliles campaign, "the central idea of our 1985 campaign is one of affirmation of Chuck Robb, of continuity." It may not travel beyond the state's borders, but the Robb Revolution has made the Old Dominion part of the New South and, in the process, made Virginians feel better about themselves as well as about the Democratic Party. For this, Democrats everywhere ought to be appreciative.