As noted earlier, Roberts conveyed his skepticism of Section 5 when he wrote for the majority in the 2009 case Northwest Austin Municipal Utilities District v. Holder. That said, Wydra told CBSNews.com, it's noteworthy that Roberts and the court did not strike down Section 5 when given the opportunity in that 2009 case.

"He has at least professed himself to be a devotee of judicial restraint," Wydra said. Given that the 15th Amendment calls on the court to defer to Congress' judgment on this issue, "then Roberts should, despite his earlier comments, uphold the pre-clearance requirement."

The changing political landscape

In his 2009 opinion, Roberts wrote that "the evil that [Section 5] is meant to address may no longer be concentrated in the jurisdictions singled out for preclearance. The statute's coverage formula is based on data that is now more than 35 years old, and there is considerable evidence that it fails to account for current political conditions. For example, the racial gap in voter registration and turnout is lower in the States originally covered by [Section 5] than it is nationwide."

Since then, however, a great deal of evidence has accrued that could reaffirm Section 5's legitimacy.

"We are on the heels of one of the most aggressive attacks on voting rights laws since the Jim Crow era," Perez said. "We had state legislatures try to change the rules of the game to keep people from voting, and in a few instances Section 5 was a tool used to prevent that."

In an October 2012 report, the Brennan Center chronicled 25 laws and two executive actions that could make voting harder passed in 19 states since 2011. Several of those laws were overturned in the courts. Some of those laws -- including voter ID laws in Texas and South Carolina -- were rejected after failing the Section 5 pre-clearance.

Pildes noted that the Supreme Court has upheld the constitutionality of voter ID laws in general, but it hasn't reviewed the specific cases in South Carolina or Texas. But whether or not the court would agree with the decision to block those laws, it's noteworthy that Section 5 was invoked at all.

"For many years, before the recent past, Section 5 had been used overwhelmingly in contexts that were not about access to the ballot box but about how districts were designed," Pildes said. "Issues of access to the ballot box are always the most troubling and always were at the core of Section 5."

Of course, many of the controversial laws passed in recent years were not in states covered by Section 5. The recourse voters have in those states proves -- as President Obama noted recently -- that Section 5 is "not the only tool" available to fight discrimination at the ballot box. Furthermore, the president is calling for strengthening that tool box. In his State of the Union address, Mr. Obama announced the formation of a bipartisan commission that over the next six months will draft a plan to reform national voting laws.