The rule required nonprofits in California to disclose top donor information with the state. The Supreme Court struck down the requirement in a 6-3 decision that split along ideological lines.
The conservative groups that sued against the California law – Americans for Prosperity Foundation and the Thomas More Law Center – said it violated the First Amendment's protection of freedom of association because the disclosure requirements created a "chilling effect" on speech and "actual and potential" donations. California, meanwhile, said it asks charities to submit their IRS 990 Schedule B forms to the state for critical law enforcement purposes and that the forms will not be made public, so there is therefore no reason to worry about chilling speech.
The court sided with the conservative groups, saying that such disclosure requirements infringe on the First Amendment.
"Our cases have said that disclosure requirements can chill association [e]ven if there [is] no disclosure to the general public," Roberts wrote. "While assurances of confidentiality may reduce the burden of disclosure to the State, they do not eliminate it."
Harris so far has been silent on the Supreme Court striking down the law she defended and tried to enforce.
California Attorney General Rob Bonta was named defendant in the case when the Supreme Court read the case, as the defendant was changed with each new state attorney general. Harris was the original defendant in the years-long legal battle.
The case was backed by almost 300 separate organizations from different sides of the political spectrum
"Americans shouldn’t have to choose between staying safe or speaking up," AFP Foundation CEO Emily Seidel said in a statement. "History shows us the ability to maintain privacy makes it possible for people to join together on causes and in movements."
"That was the case for the Civil Rights movement, marriage equality, and is still the case today," she continued. "Especially in a polarized climate, the work of addressing injustice and advocating for change is hard enough without people facing fear of harassment and retaliation from the government and from potentially violent opposition."
The vice president's office did not respond to Fox News' request for comment from Harris on the ruling.
Fox News' Tyler Olson contributed reporting