A Terre Haute attorney is making his sixth argument before the nation's highest court Wednesday, but his first before the newest justice. This time he's there on a case that could ultimately change campaign-finance disclosure rules nationally.

During an hour-long argument scheduled to begin at 10 a.m. before the United States Supreme Court, lawyer Jim Bopp faces off against the state of Washington Attorney General's Office in the case of John Doe #1, et al. v. Sam Reed, Washington Secretary of State, et al., No. 09-559. The issue is whether the state's public-records disclosure law violates the First Amendment privacy rights of voters who sign petitions to launch a referendum aimed at overturning a law allowing same-sex domestic partnerships.

Arguing for the conservative group Protect Marriage Washington that brought the suit, Bopp is arguing those names should remain private. This case is one of several Bopp is handling nationally on the broader scope of campaign-finance rules, and the outcome could play into how contributors are allowed to donate to election campaigns and get involved in political issues.

The 9th Circuit Court of Appeals in California had reversed a decision from the District Court level, which had given the sponsors an injunction against the release of the names.

Bopp said he arrived in Washington, D.C., Monday evening and is participating in a moot court today at the conservative-focused American Center for Law & Justice. Aside from the merits of the case, Bopp said he is looking forward to arguing in front of the current nine justices, including Justice Sonya Sotomayor who was appointed to the bench last year. The last case he argued before the court was the 2007-decided case of Federal Election Commission v. Wisconsin Right to Life, Inc., 551 U.S. 449 (2007), in which the justices held that issue-specific ads may not be banned in the months preceding a primary or general election.

"I do think it'll be interesting," he said, wondering what difference he'll see without aggressive questioning by Justice David Souter, who strongly supported campaign-finance regulations. "I'm looking to see how the dynamics are different."

Justices are expected to issue a decision by the time the term ends in June.