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 has agreed to consider reinstating the conviction and death sentence of a man who said he was high on meth when he killed a Kansas sheriff.

The justices on Monday said they will review a state Supreme Court ruling that granted a new trial to Scott Cheever, who admitted to shooting Greenwood County Sheriff Matt Samuels.

The Kansas court said Cheever's rights were violated during his trial because a psychiatrist was allowed to testify about Cheever's psychological records without his consent.

Samuels' death prompted changes in the Kansas criminal code to make it more difficult to purchase the ingredients used in making meth.

The case will be argued in the fall.

U.S. District Judge Reggie Walton has been appointed presiding judge of a secretive special court that oversees warrants for government surveillance in spy and terrorism cases.

Chief Justice John Roberts appointed Walton to head the Foreign Intelligence Surveillance Court effective Feb. 22, replacing Judge John D. Bates, whose term is expiring.

The court meets in secret at the federal courthouse in Washington to hear classified evidence from government attorneys. No defense attorneys are present. At least one of its 11 judges is on call to issue warrants any time of the day or night.

Walton has served on the surveillance court since 2007. He also has presided over a number of high-profile federal court cases, including last year's Roger Clemens perjury trial.