EVERY NOW AND AGAIN over the last century, we've suggested that Congress consider rectifying an old oversight that has shut out a respectable number of American citizens from its legislative doings - namely, the people of the District of Columbia, who are without full-fledged senators and representatives. Today, as the House Judiciary Committee meets to act on a proposed constitutional amendment providing congressional representation, we won't re-hash the more familiar arguments for extending this democratic right; by now, most members have heard them.

Indeed, most members of Congress do acknowledge the right of the District's residents to representation in the House - it's the Senate that has been a sticking point. By and large, this opposition has focused on language in the Constitution providing that "no State, without its consent, shall be deprived of its equal suffrage in the Senate." But during the House hearing last fall, there was extensive testimony from constitutional scholars who saw no problem with this clause. Among them was Charles Alan Wright of the University of Texas, who predicted that any challenge to the proposed amendment based on this clause would fail. "It seems to me that the clear purpose of that clause was to ensure that the Great Compromise would not be undone and that representation in the Senate would not be put on the basis of population," he stated. "That purpose is not compromised by allowing the District to have two senators any more than it is when a new state is admitted."

Similarly, Prof. Stephen A. Saltzburg of the University of Virginia Law School testified: "To be candid, I find this argument to be nonsense . . . Nothing in the language of this Article states that the Constitution cannot be amended to give entities other than states voting power in the Senate. All that is required is that a state have an equal vote. If the District is given two senators, no state is in an unequal position when compared to any other state or to the District." For that matter, if the Distrct were given representation in the House but not the Senate, the balance of the two Houses of Congress would be upset.

But the underlying reasons for opposing District representation in the Senate have more to do with politics than constitutional history. For one thing, many Republicans see the change as an automatic addition of two Democrats. Others in the club of 100 aren't anxious to have their relative influence diminished. Who knows, before we're through somebody may even argue that a limit of 100 senators is a necessary part of the conversion to a metric-decimal system.

In any event, there does seem to be strong interest this year in approving full voting representation. President Carter has endorsed it not just as a matter of local interest, but also as a part of the administration's human-rights commitments. Moreover, support for full representation was included in the 1976 platforms of the Democratic and Republican parties. Also in 1976, a majority of the House - nearly the necessary two-thirds - voted for a proposed amendment. This time, Congress should finish the job. The best sendoff would be a resounding committee vote this morning for nothing less than full representation in the House and Senate.