ewsAnalysis

WASHINGTON, Dec. 11 — The Supreme Court that upheld the new campaign finance law on Wednesday was a pragmatic court, concerned less with the fine points of constitutional doctrine than with the real-world context and consequences of the intensely awaited decision.

Although the outcome was unexpected — few people had predicted that the court would uphold all the law's major provisions so unequivocally — the majority's approach to its task should probably have come as no surprise.

It was the same 5-to-4 majority that barely six months ago navigated the court's encounter with an even more contentious issue in American life, affirmative action, and produced a decision that was similar in important ways.

Justice Sandra Day O'Connor's majority opinion in that case upheld affirmative action in higher education, drawing on a conclusion that its benefits "are not theoretical but real" and taking a posture of judicial deference to "complex educational judgments in an area that lies primarily within the expertise of the university."

The opinion left the same four justices who dissented on Wednesday fuming that the majority had evaded the command of precedents that made any official counting by race almost insuperably suspect, just as the dissenters complained this week that the majority had failed to give sufficient weight to the First Amendment rights of campaign donors and speakers.

In the campaign case, Justice O'Connor shared the assignment of writing the majority opinion with Justice John Paul Stevens. He has long been the court's most outspoken supporter of campaign finance regulation, dismissing the First Amendment objections as insubstantial. She, on the other hand, had been largely a mystery, having voted on both sides of the issue over the years while writing less than three pages of opinions in her own voice.

Unlike redistricting cases, on which Justice O'Connor has been deeply engaged, campaign finance issues "didn't seem to motivate her," Prof. Richard L. Hasen, an election law specialist at Loyola Law School in Los Angeles, said on Thursday. "We never knew where she stood," he added.

Both sides tailored their arguments in part to reach her, on the ultimately correct premise that she would probably control the outcome in the case, McConnell v. Federal Election Commission, as she has controlled so much else in a tenure of nearly 23 years. With her opinion on Wednesday, campaign finance becomes still one more area of the law — the others ranging from equal protection to religion to federalism to abortion — that reflects Sandra O'Connor's vision.

The success and failure of the competing strategies in the campaign case were telling. Opponents of the Bipartisan Campaign Reform Act, mindful of Justice O'Connor's concern for and deference to states' rights in a long series of federalism cases, attacked the section of the law that regulates various fund-raising activities of state and local party committees and limits the ability of federal officeholders and candidates to work in coordination with those committees.

"The effects of this federal intrusion will be severe," warned a brief from Kenneth W. Starr, representing the lead plaintiff, Senator Mitch McConnell, Republican of Kentucky.

When the case was argued in September, the law's effect on state parties received considerable attention. But in the O'Connor-Stevens majority opinion, the states' rights objection failed to gain any traction. "State committees function as an alternative avenue for precisely the same corrupting forces," the justices observed.

"Having been taught the hard lesson of circumvention by the entire history of campaign finance regulation," they said, Congress was well justified in including state and local party committees within the statute's regulatory reach.

In their presentation, the law's supporters emphasized facts rather than theory, presenting a vivid picture of modern political fund-raising and the consequences in all its grubby detail — and to great effect. The O'Connor-Stevens opinion referred to "reams of disquieting evidence" demonstrating that "parties have sold access to federal candidates and officeholders." The law's prohibition on the largely unregulated contributions known as soft money is justified, the opinion concluded.

Deference to Congress was a theme throughout the majority opinion. "The record amply justifies Congress's line drawing," it said at one point. "Congress is fully entitled to consider the real-world differences between political parties and interest groups," it said at another.

From a majority that included Justice O'Connor, this language was striking. In the court's federalism decisions, a five-justice majority — comprising Justice O'Connor and the four dissenters in the campaign case — has immunized state governments from various federal antidiscrimination laws, refusing to defer to Congressional judgments on a need to bring the states within the laws' coverage.

Those decisions have been increasingly controversial. Against that backdrop, it is possible to view the campaign finance decision as something of a corrective, a pragmatic intervention not only to shape the outcome of the case at hand but also to lower the temperature of an increasingly fraught relationship with another branch of government.

"The court gave Congress space to breathe," Prof. Robert C. Post of Yale Law School said on Thursday.

Professor Post said he had little doubt that Justice O'Connor's role had been decisive. "Her political antennae moved her," he said. "Things were getting pretty explosive. The tension was too high, and she understood that the rhythm of the court's relationship with Congress had to be attended to, the pace of the conversation had to be lowered."

On that theory, Justice O'Connor's central role extends even further than it appeared on Wednesday — not simply to another category on a checklist of constitutional controversies, but also to the web of relationships that anchor the court and its enormous power to the rest of the government. The current Supreme Court term is still young. Given some other cases on the docket, most notably the challenges to the Bush administration's conduct of war on terrorism, it is a role that will again be put to the test.