Chief Justice Sarah Parker administers, right, the oath of office to North Carolina Gov. Pat McCrory at the North Carolina State Capitol in Raleigh, North Carolina, Saturday, January 12, 2013. (Jeff Siner/Charlotte Observer/MCT via Getty Images)

WASHINGTON -- Any race-related emails that North Carolina Republicans may have sent in connection with the voter restrictions they passed last summer could soon be public, thanks to a ruling by a federal judge.

Before the Supreme Court's decision to strike down a key portion of the Voting Rights Act, simply demonstrating a discriminatory impact could be enough to overturn a discriminatory law. Now, in order to have North Carolina's voting law struck down, civil rights groups and the Justice Department have to demonstrate that state lawmakers deliberately engaged in racial discrimination against voters.

The sweeping law requires voters to show certain forms of photo identification, eliminates same-day registration and reduces early voting -- all measures which voting rights advocates say are intended to make it harder for Democratic-leaning minorities to vote.

The emails sent by legislators are crucial to proving racial motivations played some role in the legislation.

North Carolina wanted to keep legislator emails secret. But U.S. Magistrate Judge Joi Elizabeth Peake ruled Thursday that the state couldn't withhold all the emails. She did, however, say that North Carolina might be able to argue that emails only between legislators and their staffers could be kept private.

Of course, if legislators have nothing to hide about the motivations for passing the restrictive laws, they can individually waive their legislative immunity, as Peake noted.

Voting rights advocates welcomed the judge's decision.

"North Carolinians have a right to know what motivated their lawmakers to make it harder for them to vote," Dale Ho, director of the ACLU's Voting Rights Project, said in a statement. "Legislators should not be shrouding their intentions in secrecy. The people deserve better."