The U.S. Department of Justice, citing federal law, has blocked a portion of a South Carolina law requires voters to show a photo ID, saying the requirement puts a disproportionate burden on minorities.

Thomas Perez, the U.S. Assistant Attorney General expressed the objection in a letter written to South Carolina Attorney General C. Havird Jones, Jr. on Friday.

South Carolina, along with several other states, is required to submit changes to its voting procedures for review by the federal government under the Voting Rights Act of 1965. The state is allowed to request that the Attorney General reconsider the objection.

Under the law, a state can seek a judgment from the U.S. District Court of the District of Columbia that the proposed changes won't discriminate.

Section 5 of the state’s Act R54 law would require voters to present one of five forms of photo identification to vote in person.

“In sum, however analyzed, the state’s data demonstrate that non-white voters are both significantly burdened by section 5 of Act R54 in absolute terms, and also disproportionately unlikely to possess the most common types of photo identification among the forms of identification that would be necessary for in-person voting under the proposed law,” Perez wrote.

In assessing the impact of the photo ID requirement, Perez said the Department looked at voter registration data provided by the State Election Commission.

The data show that 8.4 percent of white registered voters lacked any form of Department of Motor Vehicles-issued ID, compared with 10 percent of non-white registered voters, the Department said.

“Minority registered voters were nearly 20 percent more likely to lack DMV-issued ID than white registered voters, and thus to be effectively disenfranchised by Act R54r’s new requirements,” wrote Perez.

He said that while non-white voters comprised 30.4 percent of the state’s registered voters, they constituted 34.2 percent of registered voters who did not have the requisite DMV-issued identification to vote.

The state’s statistics show nearly 82,000 minority citizens who are already registered to vote and who lack DMV-issued identification.

“The state has failed entirely to address the disparity between the proportions of white and non-white registered voters who lack DMV-issued identification,” Perez wrote.