Letters to the editor have blasted him. Editorials have denounced him. Members of Congress have called for his resignation, and George McGovern, indignant and eloquent, says he has "crossed a line." I am talking of Pat Buchanan, about whom, I promise, you should care not one whit. He punches the clock like you and me.

You are excused for not knowing that because Buchanan is being treated as if he were his own man -- a loose cannon at the White House. Only a year ago, though, the papers were full of stories about how Buchanan was being ignored and, indicative of political impotence, given a windowless office. He himself admitted that his influence was limited. He had wanted to put Jonas Savimbi in the hero's chair at the State of the Union message but had, alas, been overruled. The world lost yet another hero.

What was really lost was perspective. It was, of course, Buchanan who penned that now-infamous op-ed piece for The Post. In it, he enunciated the Buchanan Doctrine, which holds that you either favor the president's mindless Nicaragua policy or you are -- sorry if the shoe fits -- a commie symp: "With the vote on contra aid the Democratic Party will reveal whether it stands with Ronald Reagan and the resistance -- or Daniel Ortega and the communists." The choice is yours.

But there is another choice. And that is to recognize that Buchanan is really the president's man. On this particular issue he has been told -- or allowed -- to red bait. What this says about the character of Ronald Reagan I leave to you. But it says plenty about the president's popularity and his amazing ability to be held harmless for what he himself does. Not only do his critics pretend that Buchanan is an independent operator but -- in a telltale salute to Reagan's standing -- they call upon him to resign. Perish the thought that they should demand that Reagan fire Buchanan.

When it comes to Nicaragua, the president has chosen a certain course and wants a certain outcome: elimination of the Sandinista regime. The means to that end entails a liberal amount of 100-mule-team snake oil. A contra aid program that was (1) supposed to get the Cubans out of Nicaragua and then (2) to interdict the flow of arms to El Salvador is now (3) designed to prod the Sandinistas to the bargaining table so that they can (4) be persuaded to leave office. The fact is that (5) elimination of the communist regime has been the goal all along and the president (6) has been less than candid.

Reagan's intentions should come as no surprise. He is a fervent anticommunist -- always has been. When it comes to the Sandinistas, his ideology holds that they cannot be trusted, that they will always lie, that they will seek to spread their revolution, that they are simply an outpost of the Soviet Union. In the context of American politics, that is not an unorthodox view and maybe -- just maybe -- there is something to it.

But the president plays cute about what he wants. Other presidents -- Richard Nixon, Lyndon Johnson -- took hell for their lack of candor. Not so Reagan. He gets to hide his intentions under a bushel of terms that would make a Soviet propagandist blush -- freedom fighter, for one.

Now the call is for Buchanan to fall on his sword for red-baiting. But Buchanan is that Washington oddity -- the honest man, burning with ideological zeal, who wants to leave the world better for being in it. He gave up $400,000 a year jiving and jabbing on television, writing columns and doing speeches (no windows, though) for the $75,100 a year of a presidential assistant. He did that because he knows that Ronald Reagan is his kind of president -- that the two of them hold identical views on Nicaragua, communism and what history wil say about Democrats who, in their view, choose wrong. The old lament of conservatives is to let Reagan be Reagan. No need for that. Pat Buchanan already is.