DID FERDINAND MARCOS or his agents use a California doctor or a corporation controlled by him to funnel money to American candidates for public office in 1980? That question was raised by a document unearthed by Rep. Stephen Solarz's (D-N.Y.) subcommittee. You might think that an agency set up to enforce U.S. campaign finance laws would be interested in the answer. But not the Federal Election Commission. To be fair, the three Democrats on the commission voted to investigate. But two Republicans voted no and another abstained. Since four votes are required for an investigation, that is evidently that -- for the commission anyway.

It shouldn't be. Contributions by foreigners to federal candidates are illegal, and while there's a three-year statute of limitations on the crime, it's still worthwhile to investigate whether there has been some pattern of violations and whether candidates and campaigns can protect themselves from receiving foreign money.

The evidence unearthed by Rep. Solarz last March is a one-page summary of contributions by the Mahubay Corp. of California, controlled by Dr. Leonilo Malabed of San Francisco, who describes himself as "a friend, not a crony" of Mr. Marcos. The summary lists $51,500 to the 1980 Carter campaign, $50,000 to the 1980 Reagan campaign, $10,000 to Sen. Alan Cranston and California Lt. Gov. Leo McCarthy, and $50,000 to California Assembly candidate Larry Asera. Dr. Malabed is listed as a contributor to the Carter, Reagan and Cranston campaigns, though for lesser amounts, below the federal limits; Dr. Malabed also admits paying a California bank some $30,000 to repay a loan to Mr. Asera which he co-signed and on which the assembly candidate defaulted. One interesting question the FEC might have asked Dr. Malabed is whether he funneled money through others. Other questions could have been asked of Hawaii resident Ferdinand Marcos.

The recipients of Dr. Malabed's money indignantly deny that they had any knowledge that these were foreign contributions. There seems to be no reason to disbelieve them, and the FEC unanimously voted to dismiss the complaints against them. One can also wonder why a foreign leader interested in political influence here would cause some $30,000 to be donated to an unsuccessful candidate for the California Assembly, or why he would conclude that even $50,000 would change the policies of Messrs. Carter or Reagan. But lawbreakers don't always behave rationally. The Federal Election Commission, on this issue as on other issues from soft money to the Michigan precinct delegate primary, has ducked its responsibility to uphold the law.