The Supreme Court ruled Monday that the government can ban campaign contributions from advocacy groups, a warm-up decision to the showdown over the broader new campaign finance law.

Justices rejected a constitutional challenge to the 32-year-old federal donation ban, which applies to groups with a point of view on issues such as gun rights and abortion.

The case, involving a North Carolina anti-abortion organization, was a prelude to the court's handling of the 2002 campaign finance law.

By a vote of 7-2, the court said the right to free speech does not trump Congress' goal of limiting the corrosive effects of corporate money in politics.

Advocacy organizations maintain that their members should be allowed to pool their money and use it to elect candidates who support their issues.

The government maintained that the groups could be used to circumvent individual campaign donation limits, with little public disclosure about the source of the money.

"Any attack on the federal prohibition of direct corporate political contributions goes against the current of a century of congressional efforts," Justice David Souter (search) wrote for the majority.

Chief Justice William H. Rehnquist and Justices John Paul Stevens, Sandra Day O'Connor, Ruth Bader Ginsburg and Stephen Breyer agreed with Souter. Justice Anthony M. Kennedy agreed with the outcome.

Justices Antonin Scalia and Clarence Thomas dissented.

The donation ban is not directly related to the court's review of the new campaign finance law, commonly known as McCain-Feingold (search) for its congressional sponsors — Sens. John McCain, R-Ariz., and Russell Feingold, D-Wis.— but the ruling will be closely watched for clues to what the justices might do.

The court has scheduled a special session in September, a month ahead of the start of its regular term, to consider the law that bans corporate, union and unlimited contributions — known as soft money — to national party committees.

The new law also bars a range of interest groups, including those financed with corporate or union money and those that do not disclose their donors, from airing ads mentioning federal candidates in their districts the month before a primary and two months before a general election.

When Congress rewrote the campaign finance rules, it did not change the 1971 law that makes it unlawful for any type of corporation to give money to a federal candidate or political party.

Currently, only individuals, political parties, political action committees and other campaigns can contribute to federal candidates and national party committees. The court's ruling Monday maintains that status quo and continues a trend in which the high court has been willing to uphold limits on contributions.

In 2001, the court ruled that political parties could not spend unlimited amounts of money if they coordinated their efforts with a candidate. And in 2000, the court voted to back Missouri's contribution limits to state campaigns.

Elizabeth Garrett (search), a law professor at the University of Southern California, said the case is important because issue-oriented nonprofits have become increasingly important in campaigns.

She said it also means that provisions in the new campaign finance act that require nonprofit corporations, as well as for-profit corporations and labor unions, to use separate funds to pay for political advertisements are more likely to survive the court's review.

"The decision is a green light for other laws regulating these organizations and their involvement in campaigns, such as aggressive disclosure laws," said Garrett.

The case is Federal Election Commission v. Beaumont, 02-403.