Campaign-finance and free-speech issues are involved, and the case could reveal dynamics at the high court.
When the US Supreme Court upheld the McCain-Feingold campaign-finance law in 2003, the decision sharply split the nine-member court.
The crucial swing vote was wielded by then-Justice Sandra Day O'Connor, who sided with the court's liberal wing in a 5-to-4 decision affirming congressional limitations on certain forms of campaign speech and spending.
On Wednesday, the court revisits a key portion of that 2003 ruling – a provision that restricts issue advertisements funded by corporations and labor unions during the run-up to a federal election. But the case arrives before a different lineup of justices.
The case is being closely watched not only for the important campaign-finance and free-speech implications, but also because many court analysts are anxious to see if the same internal dynamic in last week's high-court abortion ruling will play a role in the two consolidated campaign-finance cases now before the court.
In the abortion case, the retirement of Justice O'Connor and her replacement with the more conservative Justice Samuel Alito paved the way for a conservative shift in the court's abortion jurisprudence. Election-law specialists say the same swing vote could be provided in the campaign-finance cases by either of the two newest members of the court – Justice Alito or Chief Justice John Roberts.
"All the court-watchers who paid attention to the confirmation process of John Roberts and Samuel Alito identified 'partial-birth' abortion and campaign finance as the precedents most likely to be reversed in the short term," says Nathaniel Persily, an election-law expert and professor at the University of Pennsylvania Law School in Philadelphia.
At issue in the campaign-finance cases, set for oral argument on Wednesday, is whether the Bipartisan Campaign Reform Act (BCRA) of 2002 violated the free-speech rights of a Wisconsin-based advocacy group. The group, Wisconsin Right to Life, was barred from running three broadcast advertisements critical of US Senate incumbent Russ Feingold (D) of Wisconsin in the days leading up to the 2004 election.