In a racially mixed corner of Shreveport, La., a small group of white voters protested loudly this year that they did not want to be part of a majority black district when the legislature redrew the state’s political boundaries. The Republican-led statehouse complied, drawing a line around the community to accommodate them.

That line is at the heart of a case before the Justice Department that is seen as a critical test of how the Obama administration will interpret the controversial Voting Rights Act as it rules on a new wave of redistricting plans.

The law, passed in 1965, was designed in part to prevent white lawmakers from weakening the voting strength of minorities with the deft drawing of district lines. More than a dozen states, including Louisiana, are required because of their history of discrimination to clear their redistricting plans with Justice.

But some lawmakers in those states, many of which have Republican majorities, say they do not trust the Obama administration to fairly assess their maps. This is the first time since the passage of the Voting Rights Act that a Democratic administration has been in the White House following a decennial census, when state lawmakers redraw local, state and congressional boundaries.

“We have not had to do this from a political standpoint with a Democrat in the Department of Justice,” said Louisiana Rep. Alan Seabaugh (R), who represents the Southern Hills area of Shreveport, where the objections to the Louisiana map emerged. “My concern is less with a racial motivation than it is with a political party motivation.”

A decision by Justice in the coming weeks to side with the state or with civil rights activists opposed to Louisiana’s map will signal how far the administration might go to protect minority rights in reviewing plans from other states that must get clearance, including Alabama, Alaska, Arizona, Georgia, Mississippi, South Carolina, Texas and Virginia.

Justice Department officials say their decisions will be made based on the law and facts, not politics.

“The Department’s career attorneys make decisions based on fact-intensive reviews, and not based on political considerations,” Xochitl Hinojosa, a spokeswoman for the department’s civil rights division, said in a statement. “Our attorneys use the same standards that would be applied by the court.”

Oversight needed?

The debate comes at a time when some legal scholars and political leaders are arguing that federal oversight of redistricting may no longer be necessary, now that the country has a black president and anti-discrimination laws governing elections are commonplace.

Civil rights enforcement has been a major priority for the Obama Justice Department and Attorney General Eric H. Holder Jr., a former civil rights lawyer who has vowed to make the civil rights division his agency’s “crown jewel.’’

But some civil rights groups say there are signs that the department may not necessarily be on their side. They point to Georgia, where Justice officials allowed lawmakers to pass a stringent new law requiring proof of citizenship to vote, over the objections of minority rights advocates. They say government lawyers were worried the fight would expand into an all-out challenge to the Voting Rights Act.

“I was a little concerned about the DOJ’s processing of that request from the state of Georgia,” said J. Gerald Hebert, a former Justice attorney and executive director of the Campaign Legal Center, an elections watchdog group. However, he said, in other voting rights cases to come before the department “what I have seen so far, frankly, is more aggressive enforcement of the Voting Rights Act.”

Supporters of the Voting Rights Act have reason to be worried about legal challenges. In recent years, the Supreme Court has hinted it may strike down the provision of the law — known as Section 5 — that requires some states to clear election law changes with the federal government.

“DOJ is acutely aware that Section 5 is hanging by a thread right now, so they are going to walk very gingerly in the way they enforce this,” said Nathaniel Persily, a professor at Columbia Law School and a redistricting expert.

Some states appear to be hedging their bets. The law allows states to seek redistricting approval from federal courts rather than Justice. Virginia and Louisiana took the unusual step of sending their plans to Justice as well as the U.S. District Court in Washington, where their application will be reviewed by a three-judge panel.

“It’s two bites at the apple,” said Seabaugh, the state legislator from Louisiana.

Ken Cuccinelli II, Virginia’s Republican attorney general, has called into question the relevance of the Voting Rights Act in the modern era, but said this year he has no plans to challenge the law’s constitutionality. And lawmakers in Georgia have said they may try to bypass Justice altogether by going only to the court.

Racial tensions

In Louisiana, the debate has opened up racial tensions in Southern Hills, a historically white neighborhood in greater Shreveport, Louisiana’s third-largest city.

When Democratic lawmakers proposed creating a new minority-heavy district that looped in Southern Hills, residents inundated the legislature with e-mails arguing that it would rob them of representation and that “the inclusion of Southern Hills in a minority district would potentially strip it of its identity.”

Some residents contend that the proposal itself, not their objections, is causing the racial tension and that the federal government should not be able to force its views on the state. Others said the community is diversifying, that it will probably become majority black eventually and there is no reason to hasten the change through redistricting.

“It looks like with time, the community is going to evolve anyway. I don’t see the need to force it,” said John Albritton, a former school board member and a Democrat.

Minority advocacy groups, including the NAACP Legal Defense Fund and the Urban League, say the residents’ objections are racially motivated. They say blacks in that area have long been “packed” into neighboring districts, limiting their political impact by holding down the number of majority black districts. In a letter to Justice, they argued that it is time to spread those voters out.

Calvin Ben Lester, a professor at Wiley College and a former Shreveport city councilman, said he was astonished that the white residents would so strenuously object to the proposal.

“The fact that we still have people who have these thoughts in their hearts, in their minds, and give vent to them and send them off to justify their position, it shows me that the Voting Rights Act is not just relevant but absolutely necessary,” he said. “My prayer is that the DOJ will enforce the Voting Rights Act. My prayer is that they would not shy away from what is in their purview.”

Staff writer Jerry Markon contributed to this report.