U.S. Attorney General Eric Holder announced Thursday the first step in a legal strategy by the Obama administration to enforce the Voting Rights Act despite the recent Supreme Court decision weakening key parts of the law.

In a speech to the National Urban League Conference at the Convention Center, Holder said he would seek court approval to subject Texas to the same type of federal oversight that existed between the passage of the landmark voter-protection law in 1965 and the Supreme Court's decision June 25.

The court, in a 5-4 vote, threw out the most powerful part of the act - the section that determined which states had a history of voting-rights violations and therefore required Justice Department "preclearance" for changes in voting laws.

The high court ruled that those provisions were unconstitutional unless Congress updated the law to reflect current conditions and recent history in those states.

Holder called the decision flawed. But, he said, it was not a defeat, but "a historic opportunity" to strengthen civil rights law.

Through a combination of sections of the Voting Rights Act still in effect, Holder said, the Justice Department was asking a federal court in San Antonio to require Texas to obtain specific approval - similar to preclearance - when a court establishes that intentional voting discrimination has occurred.

Holder said that type of discrimination was already determined last year, when a federal court blocked interim Texas redistricting maps, finding that the new maps would have discriminated against Latino voters.

"Based on the evidence of intentional racial discrimination that was presented last year in the redistricting case . . . as well as the history of pervasive voting-related discrimination against racial minorities that the Supreme Court itself has recognized - we believe that the State of Texas should be required to go through a preclearance process whenever it changes its voting laws and practices," Holder said.

U.S. Rep. Lamar Smith (R., Texas) decried Holder's announcement.

"The Supreme Court message to the Justice Department was clear - don't mess with Texas," Smith said in a news release. "But Eric Holder and the Justice Department aren't listening. They have decided to continue their vendetta against Texas by asking a federal judge to reinstate the preclearance requirement."

Texas State Rep. Trey Martinez Fischer, a Democrat and chairman of the state's Mexican American Legislative Caucus, applauded Holder's announcement, saying, "Sadly, racial discrimination in Texas is not a thing of the past."

While the federal court in San Antonio was reviewing the specific maps for alleged discrimination last year, a federal court in Washington was reviewing the changes as part of the standard preclearance process.

When the District of Columbia federal court declined to approve the redistricting in August 2012, Texas appealed the decision and challenged the ability of federal courts to approve state voting laws in the first place. The Supreme Court in June addressed the question in a similar case out of Alabama, Shelby County v. Holder.

It is the department's first action to reaffirm the Voting Rights Act after the Supreme Court's decision, but "it will not be our last," Holder said.

"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.

This interpretation is likely to be challenged in court, said Temple University constitutional law expert Mark Rahdert.

The Supreme Court's decision left open how much authority the executive branch would have as part of its responsibility to "take care" that the law was executed, he said.

The question is whether that "take-care" responsibility authorizes the Justice Department to establish a new "preclearance mechanism" independently of Congress, Rahdert said.

The U.S. district court in San Antonio will have to answer that question. The Justice Department filed a "statement of interest" with the court Thursday afternoon detailing the federal government's position on the Texas redistricting case, Perez v. Perry.

Drawing on how a section of the Voting Rights Act has been used similarly in other states, the filing asks the court to reinstitute a preclearance requirement in Texas.

If preclearance is restored in Texas, the state will appeal the case to the U.S. Supreme Court, state Attorney General Greg Abbott said in a conference call Thursday. He said the Justice Department statement was primarily political and "sowing racial divide."

"They seem to be using the legal system as a sword to wage political attacks rather than as some sort of shield to reduce wrongdoing," he said.

Holder's announcement may also have implications for Texas' voter ID law, which is supported by Republicans and opposed by Democrats, who argue that such laws disenfranchise their constituencies.

Texas, within hours after the Supreme Court's June decision, reinstated its voter ID law, which was previously blocked by federal courts. Abbott said the federal involvement in that case illustrated that enough federal oversight already existed.

Mark Jones, chair of the political science department at Rice University in Houston, said he thought Holder's announcement was politically motivated and centered on the voter ID law rather than the redistricting map.

"From a purely practical perspective, trying to make the rules as pro-Democrat as possible is also in the best interest of the Democratic agenda," Jones said.

Marc Morial, president and chief executive officer of the National Urban League, hailed the announcement, saying the plan "demonstrates Holder's resolve and the Justice Department's resolve to continue to enforce the Voting Rights Act with the full force of the law. That's good news. I think it's exciting news."

U.S. Rep. Chaka Fattah (D., Pa.) also welcomed the news.

"I think what the attorney general laid out in Philadelphia today sets the pace, that there will be an aggressive effort on the part of the federal government to protect people's right to vote," Fattah said, "not just in Texas but across the country."

Holder's decision is a "welcome development, but Congress still must act to devise and pass a new preclearance formula," said Rep. Bob Brady (D., Pa.). "We must work tirelessly towards breaking down barriers to the polls for eligible voters."