BY A SINGLE VOTE on Tuesday, Maryland's House of Delegates defeated ratification of the constitutional amendment that would provide representation in Congress for the citizens of the District. More than any other action so far on this question, this vote hurt -- for it came from some lawmakers who should understand the issue best. Some of them still see the amendment as a question of race, partisan politics or some sort of convoluted warping of the federal system. Then there are some who apparently bought the specious arguments set forth in a series of slightly hysterical, off-the-mark editorials in the morning Baltimore Sun -- including proposals for cockeyed and unrealistic plans, such as retrocession of the District to Maryland.

Though anybody can claim to have made the difference, Deo. Robin Ficker deserves mention, since he comes from neighboring Montgomery County. After voting yes to the amendment previously, Mr. Ficker turned against it on Tuesday. He said a weekend poll of his constituents found them opposed by a margin of 3 to 1. That, of course, is one legitimate way for a politician to reconsider a constitutional question of such importance -- and, who knows, maybe his next straw poll will find a few sympathetic voters to pull him to the other side. Some of them do recognize that their regional interests (including any "commuter" tax concerns) would be protected best by this amendment instead of either retrocession of statehood. Far more impressive than the politicians who dropped their support this time are those senators and delegates from Montgomery and Prince George's who have stood by their neighboring citizens, and who have considered -- in addition to any straw polls -- the injustice of continuing to deny civil rights to all Americans to whom the District is home. Gov. Harry R. Hughes, House Speaker Benjamin L. Cardin and a majority of members of the Maryland General Assembly surely scored no special points with constituents for supporting the amendament -- and they deserve recognition for their forthright efforts.

There is still one opportunity to save the amendment in Maryland this year, when the Senate-passed resolution comes before the House. Isn't there one more delegate who will join the majority?