The Pennsylvania Supreme Court drew new boundaries for the state's congressional districts on Monday, releasing a map that, if it stands, could play a significant role in Democratic Party efforts to gain control of the House of Representatives in the midterm elections.

Republicans in the state Legislature are expected to try to challenge the new maps in federal court, arguing that the federal Constitution gives state lawmakers, and not justices, the authority to draw voting districts.

Top Senate Republican lawyer Drew Crompton said Monday that a separation of powers case will form the essence of the GOP's argument. Crompton won't say whether Republicans will go to a district court or the U.S. Supreme Court or what type of legal remedy they'll seek.

They said they'll go to court this week to try to block new court-ordered boundaries from remaining in effect for 2018's elections.

The state's Supreme Court ruled in January that Pennsylvania's existing congressional map was an illegal partisan gerrymander that "clearly, plainly and palpably" violated the state constitution. Under that map, Republicans have repeatedly won 13 of the state's 18 House seats.

Earlier this month, the U.S. Supreme Court wouldn't stop the state court's order to redraw congressional districts.

Election analysts said that the court's new map could result in Democrats picking up three or four more seats, based on 2016 voting patterns. Critics have pointed to the current imbalance in House seats to highlight the unfairness of the current map, which was drawn in 2011 by Republicans.

Most significantly, the new map likely gives Democrats a better shot at winning seats in Philadelphia's heavily populated and moderate suburbs, where Republicans had held seats in bizarrely contorted districts, including one labeled "Goofy Kicking Donald Duck."

"It remedies the outrageous gerrymander of 2011, and that's the important thing, that the gerrymander be over," said David Landau, the Democratic Party chairman of Delaware County.

Information from the New York Times and Associated Press was used in this report.