THE STATE OF VIRGINIA is now in a bizarre situation. It has been told by a federal court to elect the members of its House of Delegates this fall under a districting plan thatis clearly unconstitutional. Atfirst glance, this seems absurd, and it is: the new legislature will have the taint of illegality upon it even before it meets. But was there a better remedy for the chaotic situation presented to the judges by the default of Virginia's political leaders?

Under the court's ruling, the delegates elected this fall can hold office for only one year, not the two years mandated by the state's constitution. New delegates will be elected next fall under a plan that will either be produced by the legislature before Feb. 1 or imposed onthe state by the judges. That may be a better practical remedy for the state's ills than the other possibilities the judges had available -- to postpone this fall's elections indefinitely, to order them conducted under the 1971, districting law or themselves to draw new district lines.

The drastic interference by a federal court in Virginia's political affairs is an outcome the state's leaders made no effort to avoid. The districting plan struck down by the judges had unconstitutionality written all over it when it was passed by the General Assembly last spring. No serious effort has been made to square its provisions with the 14th Amendment's one-man, one-vote requirement or with the federal Voting Rights Act.

Leaders of the General Assembly were warned of what was in store for the state, but they ignored the Constitution and the law as if these did not apply in Richmond. Almost all the members of the legislature, including most of those from Northern Virginia, went along with these leaders and did what they could to protect each other's districts. Gov. John R. Dalton refused to intervene and simply signed the bill. As recently as a month ago, both Democratic and Republica candidates for governor were still insisting the districting plan had no faults. All these "leaders" have been kidding themselves or, worse, kidding the public for the last six months. It has been a sorry performance by men who like to claim they are the worthy heirs of Virginia's long and proud political heritage.

The immediate impact of this decision on Virginia politics will be to throw the campaigns for the Sept. 8 primaries into high gear. But it is not even certain whether that election will be held. The decision will probably be appealed to the Supreme Court on the ground that no election should be held under an unconstitutional plan. That argument has considerable logic behind it, but this may be offset by the reluctance of judges to cancel elections.

In the long run, this decision could revolutionize Virginia politics. By forcing an election of members of the House of Delegates in 1982, the judges has given the state's Republicans a golden opportunity. If even some of the recent success of their candidates for Congress (nine winners in nine races in 1980) rubs off on their candidates for delegates when the elections are held in the same year, the Republicans could run the Democrats out of one wing of the state house for the first time in this century.

Beyond that, there is a strong implication in the judges' opinion that Virginia must move sharply toward single-member legislative districts. Such a change has been bitterly resisted in Richmond because it might alter the complexion of a legislature that is overwhelmingly white, male and conservative.

All that is in the future. Meanwhile, Virginia's voters might as well get ready to vote in September and November in elections that have been rendered ridiculous