Agreeing to hear another important case on race in America, the Supreme Court said Friday it will take up a battle over a key part of the landmark Voting Rights Act. Civil rights groups fear the court will use this case to gut the law.

Passed by Congress in 1965 and renewed four times since then, most recently in 2006, a key provision requires states with a history of discrimination at the polls to get federal permission before making any changes to election procedures -- from redrawing congressional district boundaries to changing the locations of polling places.

The law was at the core of the legal cases this year blocking strict new voter ID laws in Texas and South Carolina.

Shelby County, Ala., claims the pre-clearance requirement -- which currently covers nine entire states, 12 cities and 57 counties elsewhere -- is unconstitutional. Under the law, those states and areas are presumed to be acting improperly whenever they seek election changes and "must either go hat in hand to Justice Department officialdom to seek approval, or embark on expensive litigation in a remote judicial venue," says the lawyer for the county.

The areas covered by the law, Shelby County says, include some localities that have made substantial reforms while missing other parts of the country that have failed to root out discrimination at the polls.  "Florida has been forced into pre-clearance litigation to prove that reducing early voting from 14 days to 8 is not discriminatory, when states such as Connecticut, Rhode Island, and Pennsylvania have no early voting at all," the county says.

But the NAACP Legal Defense and Education Fund says the current map is a close enough fit to cover the areas of greatest concern.  "Congress is not a surgeon with a scalpel when it acts to legislate across the 50 states. But it can reasonably attack discrimination where it finds it," the group says.

Three years ago, the Supreme Court narrowly rejected a challenge to the pre-clearance  requirement but strongly suggested that several justices had doubts about its constitutionality, given recent electoral reforms. "Things have changed in the South," the court said in 2009.  "Blatantly discriminatory evasions of federal decrees are rare."

Last month, the Supreme Court heard another racially charged case, re-examining whether the nation's colleges can use affirmative action in admissions.

Today's Pennsylvania Supreme Court ruling on a challenge to the state's strict new voter ID law amounts to this message to the state: either prove that voters can easily get a new photo ID card or face the near-certain prospect that the state Supreme Court will block it from going into effect.

A state court judge in Pennsylvania ruled last month against a group of challengers to the new law, citing insufficient proof that it would disenfranchise minority voters. The challengers immediately appealed, and now the state's Supreme Court has overturned the lower court ruling, sending the case back to the judge with instructions to figure out what the practical implications of the law will actually be.

Here's the rub. The Pennsylvania legislature, in requiring voters to show photo ID at the polls, intended to make it easy for residents without a drivers license to get a voter ID card by showing only a minimal amount of identification when they apply for one. But the state agencies responsible for issuing voter ID cards are instead insisting on more rigorous proof of identity than the new law requires. 

The agencies are demanding that applicants produce a birth certificate stamped with a raised seal, a Social Security card, and two other forms of identification showing the current residence. The state agencies say if they give the cards out on the more relaxed basis spelled out in the new voter ID law, that would create a homeland security problem, because the cards can be used to board aircraft.  

So today, the state Supreme Court instructed the judge to take another crack at this case and determine whether the state will actually make it difficult to get one of these ID cards.

Until then, the law remains in effect. But the court made it clear today that unless the state can demonstrate that the voter ID cards can be obtained in the more relaxed manner spelled out in the new law, then the court would almost certainly block the voter ID law before the general election in November.  

The Justice Department approved New Hampshire's new voter ID, a version that is stricter than existing rules in the Granite State, but not as restrictive as other voters ID laws that the DOJ has rejected.'

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Under New Hampshire's previous rules, no ID was required as a condition of voting. Ballot clerks checked the names that voters announced at the polls, read back the addresses for verification, and handed over a ballot.

Under the state's new law, voters must present a photo ID -- a driver's license, a voter ID card, a military ID card, a US passport, a student ID card, a photo ID issued by any level of government, and any other photo ID deemed legitimate by supervisors at the polls.

A year from now, the list of acceptable ID's will be narrowed to a driver's license, a non-driver ID card, military ID, or passport.  But voters unable to produce the required identification can sign an affidavit, attesting to their identity, and cast a regular ballot. Beginning next year, any voter doing so will also be photographed.

New Hampshire's list of acceptable IDs as of 2013 is actually more restrictive than the set of IDs Texas would have accepted under that state's voter ID law, which a federal court blocked last week.

So why the difference? It seems New Hampshire's decision to also make it possible for voters without the proper ID to cast a regular ballot, provided they sign an affidavit and have their picture taken, allowed enough leeway.

The Voting Rights Act requires federal approval for election law changes in states with a history of discrimination against minority voters.  Most of the states subject to the law are in the South.  New Hampshire's change required approval because 10 townships in the state are covered by the act, even though the entire state is not.