WASHINGTON – Supreme Court justices expressed skepticism Monday about the federal government’s authority to block the governor of Alabama’s appointment of a fellow Republican to a vacant county commission seat representing a mostly black and heavily Democratic district.

The case is over whether Gov. Bob Riley needed clearance from the Justice Department under the Voting Rights Act of 1965, which requires Alabama and several other states – most of them in the South – to get federal approval before changing election procedures that affect minority voters.