WASHINGTON — The Obama administration on Thursday moved to protect minority voters after last month’s Supreme Court ruling striking down a central part of the Voting Rights Act of 1965, with the Justice Department asking a court to require Texas to get permission from the federal government before making changes.

In a speech before the National Urban League in Philadelphia, Attorney General Eric H. Holder Jr. said the request would be the first of several legal salvos from the administration in reaction to the Supreme Court’s decision. “My colleagues and I are determined to use every tool at our disposal,” he said, “to stand against such discrimination wherever it is found.”

Last month’s ruling, Shelby County v. Holder, did away with a requirement that Texas and eight other states, mostly in the South, get permission from the Justice Department or a federal court before changing election procedures. On Thursday, the administration asked a federal court in Texas to restore that “preclearance” requirement there, citing the state’s recent history and relying on a different part of the voting rights law.

Republicans harshly criticized the announcement, in a sign that both parties view the battle over voting laws as important to future elections.