Massachusetts officials came out swinging this week after Chief Justice John Roberts argued in a hearing on the constitutionality of a part of the Voting Rights Act (VRA) of 1965 that Mississippi may be more sensitive to black voting rights than Massachusetts.

That's important because Mississippi, often derided as a backward backwater due to its ugly racial history, has to run any changes to its voting laws by the US Department of Justice (DOJ), while Massachusetts, broadly seen as a paragon of the enlightened North, does not.

The argument cuts to the bone of what's in front of the Supreme Court in the case of Shelby County, Ala. v. Holder: Should the South continue to be punished for its past racism despite evidence that those days are gone, or is there another, broader imperative that Section 5 protections are necessary to guarantee the franchise for all Americans?

Section 5 requires that nine states and many other jurisdictions, mostly in the South but also including parts of the Bronx (N.Y.), "pre-clear" voting law changes with the US Justice Department due to evidence of past disenfranchisement.

While Congress handily reauthorized the VRA in 2006 for another 25 years, conservative justices on the Supreme Court, including Chief Roberts, zeroed in this week on whether Section 5 has itself become discriminatory, since many indexes suggest that blacks vote at equal or even higher rates than whites in the covered jurisdictions.

Justice Roberts pointed out as proof that Massachusetts, for example, has "the worst ratio of white voter turnout to African-American voter turnout."

Claiming Roberts is obfuscating US Census data, Massachusetts voting officials shot back.

"The concept of black communities in Massachusetts not voting is an old slur, and it’s not true,” Secretary of State William Galvin said. “I guess the point [Roberts] is trying to make is Mississippi is doing so much better they don’t need the Voting Rights Act. He can still relay that conclusion, but he shouldn’t be using phony statistics. It’s deceptive, and it’s truly disturbing.”

As it is, Roberts is reading census figures that partially support his contention, but he failed to include margins of error that could, also technically, put Massachusetts ahead of Mississippi when it comes to minority participation versus white. Also, officials noted, several other states have similar disparities as Massachusetts. At the same time, three Section 5 jurisdictions – Mississippi, Georgia and North Carolina – today have higher proportions of blacks voting than whites.

Interestingly, some political scientists also argue that Roberts's assessment didn't take into account the context of specific elections in the Bay State, and whether blacks were specifically courted – a question that would be awkward to defend if they were talking about white voters in the South.

On top of that, Roberts's jab at the Bay State is extra-prickly because Massachusetts has played a historical role as being antislavery, anti-Jim Crow, and pro-civil rights in the historical struggle over America's slave-holding legacy. Well into the 1950s and '60s, meanwhile, Southern states like Mississippi resisted mightily attempts to restore the full franchise to blacks.

But critics contend that the contemporary air of Northern superiority on racial matters shouldn't determine the plight of the VRA's Section 5. In arguments to the court, Solicitor General Donald Verilli said the need to keep Section 5 intact isn't as much about race as pernicious historical legacies in the covered jurisdictions.

But if racial voting disparities can't be proved, then, reauthorizing the VRA in 2006 "was prudent, and history is relevant, only if the citizens of the South remain more racist than the citizens of the North," writes conservative columnist George Will on Friday.

To be sure, Mr. Verilli is right that it's a problem with a heavily historical overlay, in which supporters suggest that, without the protections, discrimination could creep back in. But that argument failed to find much purchase with the court's conservative majority on Wednesday; one justice, Antonin Scalia, even suggested that Section 5 extended an unfair "racial entitlement" to blacks, a suggestion that made many observers bristle.

On PBS’s "The Newshour" Friday night, conservative New York Times columnist David Brooks called Justice Scalia’s controversial comment “obnoxious” and “ridiculous.”

None of which is to say that racism is dead in the South, a notion no one is arguing. The argument, rather, is over whether it can be demonstrated that South Carolina is objectively more racist than Indiana, for example. Both states last year passed voter ID laws, which civil rights activists say amount to a new kind of poll tax. South Carolina was challenged by the DOJ. Indiana was not.

Another Section 5 jurisdiction, Georgia, passed a voter ID law in 2006, had it approved by the DOJ, and saw its black and Hispanic voter participation rise, not just in the 2008 election but in the 2010 midterms, as well.

Mississippi's history is instructive, however, to those who support extending Section 5. Even though 37 percent of Mississippians are black, the state didn't have a black member of Congress until 1986. Today, however, 49 of 204 state legislators are black, and the state has a black congressman – a testament, most experts agree, to the success of Section 5.

Indeed, even the state's attorney general, Jim Hood, argued in a friend of the court brief that Section 5 still plays a "vital role" in ensuring minority voting rights in Mississippi.