Mark Shield's recent columun [Running With NCPAC," April 17] on the National Conservative Political Action Committee is out of a school of journalism that runs loosely with reality. I think it remarkable if The Post is not embarrassed by an article -- even if written by a columnist -- that was so entirely inaccurate.

I would like to point out that Mr. Shields never did NCPAC (or himself or The Post) the courtesy of calling me or anyone associated with NCPAC before writing his column. We might have saved him some embarrassment.

First, NCPAC never at any time published a picture of George McGovern with a target over his face, a charge on which Mr. Shield's piece relies for much of its emotional voltage. Even McGovern doesn't make this charge, and had Mr. Shields checked with us or him he would have learned the falsehood of this statement. Mr. Shields is wrong -- jarringly so.

Second, he charges that a statement in a fund-raising letter saying that Ted Kennedy could spend millions of his own money on his presidential campaign is false. At the time the letter was written, Ted Kennedy was perfectly able to spend any amount of money he chose since he had not yet accpeted matching funds, a detail Mr. Shields declines to mention to his readers.

But the most telling deception in the column regards the charge "NCPAC and Dolan censured [Senator Thomas] Eagleton for giving $75 million in aid to a revolutionary government in Nicaragua." In fact, that charge was printed in a study of Engleton's record that was intended for distribution at a press conference scheduled last year to announce NCPAC's Missouri campaign. What Mr. Shields did not mention is that we discovered the error before the press conference and promptly withdrew the item. Every single member of the media respected our position and accepted the correction on the spot. The statement about Eagleton's record was never made any other place, or made public by NCPAC or the missouri media.

But Tom Eagleton, like Mr. Shields, was desperate for a handle on the NCPAC problem. He had sent someone to our news conference who attempted, rather pathetically, to portray this incident as an example or our underhanded tactics. Engleton, the man, knew darn well we were not accusing him of voting for aid to Nacaragua; but Eagleton, the politician hungry for reelection, needed an issue against NCPAC. Ealgeton's attack on NCPAC can be viewed with the tolerance one needs to show some American politicans. But Mr. Shields purports to be a journalist and, presumably, has higher obligations. If he had engaged in even an elementary investigation of the fact, he would have discovered the substance of his charge was absolutely false. When I told Mr. Shields this story, he said he would "check with his sources." I await his retraction.

This sort of attack -- and Mr. Shields' comparison of NCPAC to Bob Guccione and Penthouse -- is fairly typical of the assaults on NCPAC, assaults that are an indication of a fashionable bigotry here in Washington, i.e., the intolerance of the liberal mind for those on the right who disagreed with them. The rule seems to be if you can't attack the substance of what NCPAC says, you either make up things about us and attack them. Alternatley, you attack our integrity, attack our motives, attack our friends or anything else that will confuse the issue. Frank Church and Birch Bayh, for example, likened us to Nazis. Tom Braden, a local radio commentator, commented that I remind him of a young man who wore jackboots. I suspect that if NCPAC had likened such liberals to communists, we would have been deservedly raked over the coals by newspapers like The Post. But somehow, the liberal elite cannot summon the moral indignation to defend conservatives who are also the subjects of smear attacks. The double standrad -- so ingrained in the parochial mind of the Washington liberal -- prohibits fair play for the conservatives.

Unfortunately, our 1981 campaign to help President Reagan pass his Economic Recovery Program through Congress has already received the same sort of treatment by those who disagree with the president's goals. Majority Leader Jim Wright issued a five-page news release attacking us. Not once did he challenge a single statement about his record. He did accuse us of supporting Kemp-Roth to benefit our wealthy contributors, a curious statement since the average contribution to NCPAC is approximately $20.

Paul Sarbanes (D-Md.) called us forces of negativism, ad infinitum.

All of these charges have one thing in common. They do not question the accuracy and truth of the statements we make. These politicans do not and could not deny that they oppose the Reagan Economic Recovery Program, and that they voted for billions in new federal taxes and spending in their tenures in Congress. But they do realize the constituents might be a little upset to learn about their voting records (records that are, by the way, enormously underreported by the media), so they talk about things that have nothing to do with the real issue -- their liberal voting record.

Believe me, if the voters in Maryland really support Sarbanes in his support of $231 billion in new federal spending since he's been in the Senate, or for $249 billion in new federal taxes, then he has nothing to fear from our campaign. All we are going to talk about is his record. If the voters find it lacking, they'll do something about it. If they support it, my guess is that Sarbanes and others will become more popular because of our effort, not less.

Let's get down to what's really bothering Mr. Shields. What he and his political allies are objecting to is not what we say or even how we say it. In the face of the failure by much of the media to expose duplicitous politicans who engage in liberal votes in Congress and conservative rhetoric at home. NCPAC has taken up the cudgels and effectively so. This bothers Mr. Shields and his polticial friends, so they resort to false charges, tawdry journalism and a bit of the old smear.