In general, partisan balance is not usually a goal when redistricting. You could certainly argue that partisan balance and maximizing the number of competitive districts should be among the criteria, but, in general, they are not. Instead, a nonpartisan map usually means a partisan-blind map. It strives for compact districts that respect communities of interest, with little regard for the partisan outcome.
A decision to pursue partisan balance in Pennsylvania is particularly significant because Democrats are at a clear geographic disadvantage. They waste a lopsided number of votes in heavily Democratic Philadelphia and Pittsburgh; the Republicans don’t waste as many votes in their best areas, and so the rest of the state (and therefore its districts) leans Republican. As a result, a partisan-blind map will tend to favor the Republicans by a notable amount.
The new Pennsylvania map released Monday meets every standard nonpartisan criteria. It’s compact, minimizes county or municipal splits and preserves communities of interest. But it consistently makes subtle choices that suggest that partisan balance was an important consideration.
The court’s apparent prioritization of partisan balance is something of a surprise, since the court’s order didn’t specify that partisan balance was an objective for the new map. That’s also probably why the map is even more favorable to the Democrats than the plans that Democrats submitted themselves. Republicans in the State Legislature will probably be deeply upset and could try to challenge the new maps in federal court.
On the other hand, the new map is quite fair if it’s judged based on the relationship between seats won and the statewide popular vote. By that measure, it may still tilt slightly to the Republicans. If you value partisan fairness, you can cheer the result. If you think maps should be partisan-blind, you can argue that the map was drawn to the advantage of Democrats.