For months, Attorney General Eric Holder Jr. has insisted in speeches that the U.S. Department of Justice will remain aggressive in protecting the right to vote no matter how the U.S. Supreme Court ruled in the latest challenge of the Voting Rights Act.

Holder's words will be put to a test after the high court on June 25 struck down a key anti-discrimination provision in federal voting rights law. Last week, Holder said the "decision represents a serious setback for voting rights — and has the potential to negatively affect millions of Americans across the country."