The Supreme Court's conservative justices voiced deep skepticism Wednesday about a section of a landmark civil rights law that has helped millions of Americans exercise their right to vote.

In an ominous note for supporters of the key provision of the Voting Rights Act, Justice Anthony Kennedy both acknowledged the measure's vital role in fighting discrimination and suggested that other important laws in U.S. history had run their course. "Times change," Kennedy said during the fast-paced, 70-minute argument.

Kennedy's views are likely to prevail on the closely divided court, and he tends to side with his more conservative colleagues on matters of race.

The court's liberals and conservatives engaged in a sometimes tense back-and-forth over whether there is an ongoing need in 2013 for the part of the voting rights law that requires states with a history of discrimination, mainly in the Deep South, to get approval before making changes in the way elections are held.

The Supreme Court will hear an appeal from a jilted woman who was convicted under an anti-terrorism law for spreading deadly chemicals around the home of her husband's mistress.

The justices said in an order Friday that they will revisit the case of Carol Anne Bond, a Pennsylvania woman who was given a six-year prison term for violating a federal law involving the use of chemical weapons.

In 2011, the court unanimously sided with Bond to allow her to challenge her conviction despite arguments from federal prosecutors and judges that she shouldn't even be allowed to appeal the verdict. Lower courts subsequently rejected the appeal.

Bond, from Lansdale, Pa., near Philadelphia, says she is in prison over a domestic dispute that resulted in a thumb burn for a onetime friend who became her husband's lover. Bond was convicted in federal court of trying to poison the woman by spreading toxic chemicals around her house and car and on her mailbox.

Her argument is that the case should have been dealt with by local authorities, as most crimes are. Instead, a federal grand jury indicted her on two counts of possessing and using a chemical weapon. The charges were based on a federal anti-terrorism law passed to fulfill the United States' international treaty obligations under the 1993 Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction.