Washington ? The Supreme Court agreed Friday to clarify how legislative line-drawing must be done to protect the voting rights of minorities, a subject that has sharply divided the court in the past.

States and local governments must redraw boundaries every 10 years to reflect population changes.

The justices will consider whether to reinstate legislative district lines adopted in Georgia. A lower court rejected the boundaries last spring, ruling that state lawmakers wrongly reduced minority voting strength in several Georgia Senate districts.

The case gives the Supreme Court a chance to spell out how officials can redraw districts that previously had dense minority populations, without violating the federal Voting Rights Act.

Expected by July, the decision will apply to governments required by the Voting Rights Act to get their plans cleared by the federal government or a court, including most Southern states.

The Supreme Court has already held that the federal government has limited authority to veto elections changes. In 2000, justices ruled 5-4 that the government cannot reject proposed changes in election systems, even if they are discriminatory, so long as the changes leave minorities no worse off than they were before.

The challenged Georgia redistricting plan, drawn by the Democratic-controlled Legislature, shifted black voters from safe Democratic districts into adjacent districts. It was part of a strategy to oust Republicans.

After losing in the lower court, Georgia lawmakers redrew the Senate boundaries, and elections occurred in November in the approved districts.

The elections went badly for Democrats. The state elected its first Republican governor in 130 years. Democrats lost state Senate seats in the election, and Republicans took control of the Senate after the election when four Democrats switched parties.