NYT editorial begins:

As long as politicians are entrusted with drawing legislative maps, they will use their pen to gain partisan advantage. Courts generally do not interfere with that process, but there are limits to this where race is involved. The problem is figuring out which motive — race or partisanship — underlies the redistricting. On Wednesday, the Supreme Court considered this issue in a thorny case that could have significant implications for the future of the Voting Rights Act.

It concludes:

A purpose of the voting rights law was to preserve the voting power of minority groups in different ways depending on local conditions. This kind of rigid redistricting isolates minority voters and limits their political power. It is up to the justices to reaffirm the law and, as the election-law scholar Justin Levitt has written, to stop lawmakers from turning “a refined and sophisticated piece of federal legislation into a cartoon.”