SEN. MITCH McConnell (R-Ky.), the chief congressional roadblock to any campaign finance reform, filed an amicus brief the other day asking the Supreme Court to revisit the question of whether any contribution limits are permissible under the First Amendment. Last we checked, this was a settled matter of law; contribution limits were upheld by the Supreme Court in the landmark case of Buckley v. Valeo. But Mr. McConnell claims -- both on analytical grounds and because of the effects of inflation -- that the federal limits have become a serious hindrance to protected speech. His brief is a frontal assault on our already weak campaign finance laws.

The case in which Mr. McConnell's brief was filed is hardly less of an assault. On its face, it is a challenge only to Missouri's state contribution limit of $1,075, which it says fails to meet the requirements the court laid out in Buckley. But the Missouri contribution limits, which were struck down by a federal appeals court last year, are quite similar to the federal limits both in their intent and in the magnitude of the contributions they allow. A decision by the Supreme Court agreeing that they are unconstitutional would cast grave constitutional doubt upon the federal limits. If the Supreme Court does not side with reform advocates on this one, the battle for a balanced approach to campaign finance will be seriously set back.

On the other hand, a decision upholding the Missouri law could be a welcome win for reform, a restatement of Buckley's important premise that controlling corruption and the appearance of it make up a compelling interest that justifies some regulation of campaign finance. There is reason to be hopeful on this score. The decision the Supreme Court is reviewing is a pretty shoddy piece of work that provides an ample opportunity for a court so inclined to reiterate the constitutionality of contribution limits. To have the courts repeat clearly that regulation is permissible in some instances would be a useful clarification that the First Amendment -- while clearly at the center of the discussion of money and politics -- is not the end of that discussion.