The 1960s-era provision largely singled out states and districts in the South — those with a history of discrimination — for special screening by the federal government over changes to their laws. But the court ruled 5-4 that the formula determining which states are affected is unconstitutional, and said Congress could try to draft a new provision.

The justices said that the law Congress most recently renewed in 2006 relies on 40-year-old data that does not reflect racial progress and changes in U.S. society.

“In 2006, the Act was reauthorized for an additional 25 years, but the coverage formula was not changed. Coverage still turned on whether a jurisdiction had a voting test in the 1960s or1970s, and had low voter registration or turnout at that time,” Chief Justice John Roberts wrote.

He clarified that the provision requiring advance approval of voting law changes — known as Section 5 — was not being struck down. Rather, the court found that the provision pertaining to the formula, known as Section 4, was unconstitutional. The decision, though, challenges the overall practice of federal screening unless and until Congress addresses the formula.

The decision means that a host of state and local laws that have not received Justice Department approval or have not yet been submitted will be able to take effect. Prominent among those are voter identification laws in Alabama and Mississippi.

Going forward, the outcome alters the calculus of passing election-related legislation in the affected states and local jurisdictions. The threat of an objection from Washington has hung over election-related proposals for nearly a half century. At least until Congress acts, that deterrent now is gone.

Roberts argued that these states and the conditions in them have “changed dramatically” over the years.

“The tests and devices that blocked ballot access have been forbidden nationwide for over 40 years. Yet the Act has not eased (Section 5’s) restrictions or narrowed the scope of (Section 4’s) coverage formula along the way. Instead those extraordinary and unprecedented features have been reauthorized as if nothing has changed, and they have grown even stronger,” he wrote.

The decision comes five months after President Obama, the nation’s first black chief executive, started his second term in the White House, re-elected by a diverse coalition of voters.

The high court is in the midst of a broad re-examination of the ongoing necessity of laws and programs aimed at giving racial minorities access to major areas of American life from which they once were systematically excluded. The justices issued a modest ruling Monday that preserved affirmative action in higher education and will take on cases dealing with anti-discrimination sections of a federal housing law and another affirmative action case from Michigan next term.

The court warned of problems with the voting rights law in a similar case heard in 2009. The justices averted a major constitutional ruling at that time, but Congress did nothing to address the issues the court raised. The law’s opponents, sensing its vulnerability, filed several new lawsuits.

The latest decision came in a challenge to the advance approval, or preclearance, requirement, which was brought by Shelby County, Ala., a Birmingham suburb.

The lawsuit acknowledged that the measure’s strong medicine was appropriate and necessary to counteract decades of state-sponsored discrimination in voting, despite the Fifteenth Amendment’s guarantee of the vote for black Americans.

But it asked whether there was any end in sight for a provision that intrudes on states’ rights to conduct elections, an issue the court’s conservative justices also explored at the argument in February. It was considered an emergency response when first enacted in 1965.

The county noted that the 25-year extension approved in 2006 would keep some places under Washington’s oversight until 2031 and seemed not to account for changes that include the elimination of racial disparity in voter registration and turnout or the existence of allegations of race-based discrimination in voting in areas of the country that are not subject to the provision.

The Obama administration and civil rights groups said there is a continuing need for it and pointed to the Justice Department’s efforts to block voter ID laws in South Carolina and Texas last year, as well as a redistricting plan in Texas that a federal court found discriminated against the state’s large and growing Hispanic population.

Advance approval was put into the law to give federal officials a potent tool to defeat persistent efforts to keep blacks from voting.

The provision was a huge success because it shifted the legal burden and required governments that were covered to demonstrate that their proposed changes would not discriminate. Congress periodically has renewed it over the years. The most recent extension was overwhelmingly approved by a Republican-led Congress and signed by President George W. Bush.

The requirement currently applies to the states of Alabama, Alaska, Arizona, Georgia, Louisiana, Mississippi, South Carolina, Texas and Virginia. It also covers certain counties in California, Florida, New York, North Carolina and South Dakota, and some local jurisdictions in Michigan. Coverage has been triggered by past discrimination not only against blacks, but also against American Indians, Asian-Americans, Alaska Natives and Hispanics.

Towns in New Hampshire that had been covered by the law were freed from the advance approval requirement in March. Supporters of the provision pointed to the ability to bail out of the prior approval provision to argue that the law was flexible enough to accommodate change and that the court should leave the Voting Rights Act intact.

On Monday, the Justice Department announced an agreement that would allow Hanover County, Va., to bail out.

Even as the freshly minted Obama administration was pledging a “new era of open government” in 2009, officials were quietly adding new rules that had the potential to slow down public requests for documents.

Those rules, detailed in memos reviewed by FoxNews.com, could even trip up present-day efforts to dig into the IRS’ practice of targeting conservative groups. The rules detailed in the memos largely emanated from the Treasury Department and, specifically, the IRS.

“It would seem to repudiate this notion that this is going to be the most transparent government in history,” said Dan Epstein, executive director of Cause of Action, the group that first obtained the memos.

The memos follow reports about the administration’s use of private email accounts, and coincide with ongoing debate about government transparency — particularly with recent disclosures about widespread surveillance programs.

Epstein said the document request procedures are “troubling” since the media are “really concerned about the limits of government power.”

According to the documents, the Treasury Department in 2009 set up an additional review for requests involving “sensitive information,” which covered a broad range of items. The White House sometimes got involved, slowing down the process. The IRS also acknowledged having another review process for requests from “major media,” but not for requests from private individuals.

Members of the media often try to obtain documents not readily available by citing a law known as the Freedom of Information Act. The Treasury Department, though, in late 2009 erected speed bumps for some so-called FOIA requests.

The rules were detailed in a November 2010 memo and report sent from the Treasury inspector general to Sen. Charles Grassley, R-Iowa.

The documents showed the Treasury Department set up an additional “formal level of review” for requests for “sensitive information.” This category would cover everything from emails to memos to calendars to travel logs for top department officials, legal advisers, senior advisers and others.

Once a request was deemed “sensitive,” it would then go before a “review committee,” made up of officials from several Treasury offices.

Further, the document said a special report would be prepared for IRS requests from “major media.” This covers requests from traditional news media as well as bloggers, and according to the report covered information that “was likely to attract news media or congressional interest, involved large dollar amounts, or involved unique or novel issues.”

This report would then be sent to a higher-up in the division who decided whether the material should be disclosed.

The report repeatedly said that, in most cases, political appointees were not involved in these decisions, and that the agencies have no procedures to allow that.

But Epstein said these rules could cause problems as Congress and the media dig deeper into the origin of the IRS practice of singling out conservative groups for additional scrutiny.

He pointed to another memo, dated April 15, 2009, from then-White House Counsel Greg Craig that urged “executive agencies” to consult with his office “on all document requests that may involve documents with White House equities.” Craig said this pertains to everything from FOIA requests to congressional requests to subpoenas.

This practice apparently dates back to 1993. The Treasury IG memo cited this, and described the White House involvement as “minimal and limited.” However, the report also said the White House involvement “was responsible in several cases for adding a significant processing delay,” which in Treasury’s case slowed them down.

“It actually is heavily ironic in the realm of transparency,” Epstein said.

He pointed to edicts and memos early on in the first term of the administration stressing transparency. Obama issued a January 2009 directive calling for an “unprecedented level of openness.”

Attorney General Eric Holder in March 2009 directed all Executive Branch departments to use a “presumption of openness” when dealing with FOIA requests.

To that end, the administration has instituted several other transparency initiatives. It has followed through on requiring Cabinet secretaries to hold Internet town hall discussions, set up a comprehensive website to track stimulus spending, and set up a national declassification center.