"WELL, OF COURSE I'd like to help," Joan Kroc said when called by Democratic national chairman Paul Kirk. "Put me down for $1 million." It was, for Democrats, a record-breaking contribution, given apparently because Mrs. Kroc thinks that defense spending is too high and that a Democratic president would reduce it.

But, you may ask, aren't such large contributions illegal under federal law? There's a $25,000 limit on what an individual can give a party for federal elections. The other $975,000 of Mrs. Kroc's $1 million will go into the Democrats' "nonfederal account," to be distributed to state and local parties in amounts legal under state laws. This is "soft money," and under the current loose accounting rules permitted by the Federal Election Commission much of it can be spent on activities -- registration, voter turnout, party-building -- that can help a party's candidates in federal contests. Yet there's no requirement that the $975,000 in soft money be reported centrally.

Mr. Kirk chose in this instance to disclose the contribution. But he and other Democrats refuse to disclose any of the names of those who gave the party $2.7 million in soft money last year. They will not even make limited disclosure, as the Republicans have. Thus you have a huge loophole in federal disclosure laws: there is no public record of who gives the parties millions of dollars that is centrally contributed and centrally disbursed.

Two things can be done to close the soft money loophole. One is to rewrite the law, and Sen. David Boren (D-Okla.), prodded by Republicans, has put soft-money disclosure into his campaign finance reform bill. Unfortunately, Republicans have kept the bill from coming to a vote. Meanwhile, the FEC should write regulations that effectively prevent nonfederal money from being used to affect federal elections. A federal district judge in a suit brought by Common Cause ruled earlier this month that the FEC must do just that. This is an unusual interference by the courts in the administrative process, and the FEC may be tempted to appeal. The better course would be to draw up effective soft-money regulations, so that the parties are not in a position to make themselves beholden to big contributors, whose motives may not be as pure as Mrs. Kroc's and whose names need never be disclosed to the public.