Justices on Pennsylvania's highest court are considering whether its congressional district map violates the state constitution and should be redone.
The state Supreme Court will hold oral arguments Wednesday in a challenge to the map after a lower court judge said late last month it should be upheld.
Democratic voters are suing, claiming the district lines drawn by Republican legislators in 2011 improperly punished them for political expression and association.
A Republican judge on Commonwealth Court said the plaintiffs didn't prove the map runs afoul of the state constitution.
A divided panel of three federal judges last week also upheld the maps in a separate case.
The justices voted 4-3 in November to put the case on a fast track, with one Democrat joining both Republicans in opposition.