THE LETTER DID NOT COME with mail call. It was delivered by the mail clerk to the company commander who sent the company clerk to the barracks to announce that a letter had arrived. It was a very special letter, a letter from a United States senator, and when it came everyone acted as if something very important has happened. It was the sort of letter you cannot get from your senator if you live in Washington.

This was 1964. This was the time of the Republican National Convention, of the buildup for Vietnam, of the Tonkin Gulf and Lyndon Johnson and Barry Goldwater. It was a tense time, and on the black-and-white television in a corner of the enlisted man's club at Ford Leonard Wood, Mo., Kenneth Keating, then a senator from New York, registered his disapproval of the GOP nominee by walking out of the hall.

I wrote him. I typed out the letter the next morning in the orderly room (you thought maybe I was a tank repairman?) and sent if off and thought no more of it. I told him I thought he had done a brave thing, the right thing - something like that. He wrote me back. The letter caused quite a commotion.

They came and got me and they took me to the orderly room and they showed me the letter. They wanted me to open it here, but I did not. I put it in my pocket and took it back to the barracks. It was a nice letter - a thank-you note, really, but no one knew that but me. All the others knew is that I had received a letter from my United States senator and, for a while at least, it was better than a promotion to sergeant.

So now there is this wonderful debate about of Columbia - two senators and probably one representative - and no one talks about letters. They talk instead about how the District is likely to elect three black people although no one ever faults, say, Utah, for electing only white people, usually Mormons at that. People talk also about how the representatives from the District are likely to be Democrats but how that is different from most other places nowadays is beyond me. Besides, no one ever attempted to disenfranchise Nebraska for sending nothing but Republicans to Congress.

There are even some who think the District should not have a vote in Congress because it is a place where bureaucrats live. This is the argument put forth by columnist Michael Novak, although he does not suggest that the vote be withheld from suburban Virginia or Maryland or, for that matter, Sacramento, Calif., a city where bureacrats are not unknown. Anyway, if we are to start awarding the vote on the basis of occupation, I don't know what we'll do with Las Vegas.

People talk about how the District's representatives would be pro-abortion or pro-welfare or pro-union as if these issues are forever, and will not change in time. In fact, there is no telling what the representatives from the District will be - white, black, male, female - since the population is changing and since horrors -Washingtonians may wind up choosing someone on some other basis than race. This, in fact, has already happened.

People talk about how Washington already is this favored place where federal dollars are bountiful and everyone is on easy street, thanks to the hard-working folk of other places. This may or may not be the case and I will admit that I do use parks tended by the Interior Department and ride roads paved by the Feds and maybe, just maybe, Washington does take in more money than it puts out. So do some of the states.

There is, of course, a constitutional consideration - the issue of what the framers intended when they did their framing. It's hard to tell. They made Washington a federal district, not a state, but they clearly did not envision a city of 700,000. At any rate, they had less confidence in their own infallibility than some of the people who have followed them. They, at least, provided for a means to amend the Constitution. Possibly they thought times would change.

Now, I'll tell you, I can live either way - with voting representation or without. Nothing much will change. My garbage will get picked up and the traffic lights on New York Avenue will not work and the police helicopter will circle Rock Creek Park at night for no apparent purpose other than to keep alive the Batman legend. Life will go on.

But back when I was in the Army, a letter from a senator was a very big deal and back then, I admit, I thought all soldiers had senators but back then I was wrong. Soldiers from Washington did not. Some 237 of them died in Vietnam and not a one of them had the slightest say in what happened to them. They couldn't even write a letter to their senator.

It's the sort of letter you cannot send if you live.