Thirty years ago, the U.S. Supreme Court compromised the First Amendment when it ruled that the Constitution’s prohibition on laws regulating free speech did not apply to limits on donations to political campaigns. Ever since, Congress, state legislators, and voters have struggled to apply the court’s logic, with varying degrees of success and plenty of unintended consequences.

The result has been a growing thicket of laws and rules regulating political speech, each one more complicated and cumbersome than the ones before it.

Now even the court itself is confused about what to do, as its fractured ruling in a Vermont case decided last week shows. That decision is a bad omen for a similar proposal headed for the California ballot in November.

The 6-3 decision struck down campaign spending and contribution limits Vermont adopted in 1997. Spending limits, the court said, have always been prohibited by the Constitution, as interpreted by the court in the landmark 1976 ruling in Buckley v. Valeo, and Vermont failed to demonstrate how its spending limits were any different.

Contribution limits, however, are allowed _ under certain circumstances, the court has said since Buckley. The trouble is figuring out which circumstances.

The court has said that if limits on contributions are too low, they represent an unconstitutional infringement on free speech. But how low is too low? Vermont’s caps _ $400 to candidates for governor for a primary and general election combined _ were too low, the court said.

Justice Stephen G. Breyer, writing the main opinion, used logic reminiscent of Justice Potter Stewart’s famous admonition about obscenity that could be banned by government: “I know it when I see it.” Breyer noted that Vermont’s limits were lower than any others in the country, then contradicted himself by calculating that the caps, in proportion to the state’s population, were actually higher than Missouri’s, which the court had previously upheld.

But Breyer wrote that Vermont’s caps were still “suspiciously low” and would soon become “too low” because, unlike Missouri’s limits, Vermont’s were not indexed to inflation. He also said Vermont’s limits were more troubling because they applied not just to individuals but to political parties, hindering the ability of small donors to act collectively. Because the limits also applied to the out-of-pocket expenses of campaign volunteers, they would too severely limit the ability of citizens to donate their time, Breyer wrote.

And so on. This sort of micro-evaluation, while perhaps intriguing to political junkies, leaves legal experts with little concrete guidance about what constitutional standard the court will apply in the future to judge the permissibility of such limits.

Only one justice _ Chief Justice John G. Roberts _ joined Breyer’s opinion in full. Justice Samuel Alito joined in the judgment but said he thought Breyer went too far in writing that the court’s original ruling in this field, Buckley, should be upheld. Alito did not say he would reverse Buckley. He just did not want the court to go on record addressing the question.

Justice Anthony Kennedy, meanwhile, also agreed that the Vermont limits were unconstitutionally low, but said he thought Buckley should at least be reviewed.

Justice Clarence Thomas, joined by Antonin Scalia, said clearly they would reverse Buckley, probably prohibit all contribution caps as unacceptable limits on speech, and leave it to voters to decide whether or not the candidates are corrupted by money.

On the dissenting side, Justice John Paul Stevens argued that Vermont’s caps should stand. Finally, David Souter and Ruth Bader Ginsburg, in a joint dissent, said not only should the caps stand, but the court should rule that limits on campaign spending are constitutional.

That means four of the nine current justices are at least open to the idea of getting the government out of the business of regulating campaign donations, while perhaps three want the government freed to regulate even more.

California, meanwhile, is poised to vote in November on a measure that would create a system for public financing of campaigns while also limiting private contributions to $1,000 in statewide races, a level that, as a proportion of the state’s population, is several times lower than the Vermont caps the court just struck down.

But California’s limits would be indexed to inflation, so maybe that makes them constitutional. Who knows?

(Daniel Weintraub can be reached at dweintraub(at)