Adam Liptak for the NYT:

The Supreme Court on Monday seemed skeptical of California’s demand that charities soliciting contributions in the state report the identities of their major donors.

A majority of the justices appeared to agree that at least the two groups challenging the requirement — Americans for Prosperity, a foundation affiliated with the Koch family, and the Thomas More Law Center, a conservative Christian public-interest law firm — should prevail in the case.

It was less clear whether the court would strike down the requirement entirely for all charities as a violation of the First Amendment’s protection of the freedom of association. And the justices gave few hints about whether their ruling, expected by June, would alter the constitutional calculus in the related area of disclosure requirements for campaign spending.

Justice Stephen G. Breyer repeated concerns expressed in supporting briefs that the case could have broad implications. “This case is really a stalking horse for campaign finance disclosure laws,” he said.