WASHINGTON — Attorney General Eric Holder announced Thursday the Justice Department is opening a new front in the battle for voting rights in response to a Supreme Court ruling that dealt a major setback to voter protections.

In a speech to the Urban League in Philadelphia, the attorney general said the Justice Department is asking a federal court in San Antonio to require the state of Texas to obtain approval in advance before putting future voting changes in place.

This requirement to obtain "pre-approval" from either the Justice Department or a federal court before making changes to voting laws is available when intentional voting discrimination is found.

It is the department's first action to protect voting rights following the Supreme Court's decision on June 25, "but it will not be our last," Holder said in prepared remarks.

"Even as Congress considers updates to the Voting Rights Act in light of the court's ruling, we plan, in the meantime, to fully utilize the law's remaining sections to ensure that the voting rights of all American citizens are protected."

Holder said that based on evidence of intentional racial discrimination presented last year in the redistricting case in Texas, "we believe that the state of Texas should be required to go through a preclearance process whenever it changes its voting laws and practices."

In Texas, there is a history of "pervasive voting-related discrimination against racial minorities," Holder added.

The Supreme Court, on a 5-4 vote, threw out the most powerful part of the landmark Voting Rights Act, the law that became a major turning point in black Americans' struggle for equal rights and political power.

The attorney general called the Voting Rights Act "the cornerstone of modern civil rights law" and said that "we cannot allow the slow unraveling of the progress that so many, throughout history, have sacrificed so much to achieve."