DEMOCRATIC NATIONAL Chairman Paul Kirk is persisting in his work of dismantling much of the apparatus the rules revisers created in the 1970s -- and it's probably a good thing. In his first weeks in office, he denied official party status to the caucuses that had grown up in Democratic headquarters. Then he proceeded to abolish the party's midterm mini-convention. Now he's calling for a 1988 party platform that is "not very long" and that avoids "detailed legislative laundry lists and a buzzword for every group."

All of this is entirely understandable if you begin from the premise that Mr. Kirk wants his party to be able to win a national election. The prominence of the party caucuses turned off many voters, the mini-conventions had become forums in which national candidates tried to outbid each other for the support of every special interest group and exotic constituency, and the party's recent platforms had been full of boilerplate from the National Education Association down to every little provider of testimony that could slip into the hearing schedule. The 1984 document runs nearly 30,000 words. We bet you didn't read any of it, and we suspect most Democratic politicians are just as glad you didn't.

Theoretically, platforms have a useful purpose: to spell out what a group of politicians who together form a political party will do if they are elected to office. But in the 1980s, national convention delegates are responsible not to masses of party members in the 50 states but to the presidential candidates who select almost every one of them, and the platform committee hears less from citizen-politicians out there than it does from Washington interest-group lobbyists. Voters look to candidates' speeches and statements for clues to what they would do in office. The platform is read mostly by political opponents, who hope to find something in it to embarrass the party's candidates, and generally succeed.

The Democrats have tried a short platform before. In 1944 Franklin Roosevelt, tired of intraparty squabbling in the midst of war, insisted on a brief platform. It might be nice if the Democrats could write a platform that really meant something. Failing that, Mr. Kirk has the right idea