What exactly happened here. Im assuming Republicans sued and a court sided with them and drew a new map? Could Democrats use this precedent in a state like North Carolina, Ohio, Pennsylvania, or Michigan, all states with henious gerrymanders like the 1981 New Jersey one?
The Supreme Court overturned the map in 'Karcher v Daggett'.
Before that decision, there was a presumption that you could get by with less than 1% deviation.
What the Supreme Court ruled was that the standard of equality was the minimum practicable, which means "capable to be done or put into practice successfully".
The decision reaffirmed a two-prong test.
(1) Plaintiffs must be able to demonstrate that they can produce a plan with greater equality.
(2) If they do so, then the State must justify its greater inequality.
The plaintiffs were able to demonstrate greater equality by swapping a few whole townships between districts.
The State of New Jersey gave as their justification that they were trying to protect the voting rights of Blacks in Newark and Camden; and that the undercount was greater than the deviation between districts.
New Jersey had redistricted in 2001, and then after complaints from Blacks had drawn a new map in 2002, which was the one that was being contested. While it was true that the intent of that map was to protect the voting rights of Blacks, there was no evidence that the variation in population between districts had anything to do with it, other than the map had been drawn hastily in 2002.
And there was no evidence that the variation in district population had anything to do with a differential undercount. Theoretically, if you knew the undercount associated with an area, you could get a "true population" and draw districts based on that. But New Jersey had made no attempt to do that. While the Census Bureau makes estimates, of the undercount they are very coarse (eg whites in the South - Delaware and Florida to Oklahoma to Texas are equally as likely to be missed). They might be able to tell that if they counted 1000 people in an area that they likely missed 11, give or take 20 (they might have double counted as many as 9 people or missed 31 persons.
On remand, the district court selected one of the plans that was submitted. The SCOTUS declined to stay the plan that was chosen (New Jersey wanted them to force the use of a plan that they felt more closely reflected the will of the legislature).
Since 'Karcher' (in 1983) it has been conventional wisdom that congressional districts had to have precise population equality (or within 1). Since 1990, the Census Bureau has produced population counts to the block level, so it possible to to reach equality by simply picking out blocks, and can easily be done on a PC.
If you are a legislature, you run the risk of having more deviation, and a plaintiff topping it. If you were using whole townships, you can't use the justification "we were using whole townships", since the court will say "you can use whole townships and get better equality". So you need some additional justifications, such as more compactness, or voting rights, etc. "We were trying to gut the Democrats" won't work. While redistricting is inherently political, you can't use greater inequality to achieve it.
But if you go to precise equality, a plaintiff can't beat it. Can you produce more equal districts than were used in Ohio, Pennsylvania, Maryland, Illinois, Michigan, or North Carolina?
Last year, 'Tennant v Jefferson' permitted clarified 'Karcher v Daggett'. Jefferson County, which is in the tip of the eastern panhandle of West Virginia sued because they didn't like being in the same congressional district as Charleston. Since "we don't like being in the same district as Charleston" is not a reason for suing, they claimed that the districts were not compact, and were not as equal in population as possible - because West Virginia was one of the few states that continued to use whole counties. But they were within 1%.
The district court, quoting Bob Dylan's, "the times they are a-changin", ruled that West Virginia could use computers to split apart counties, and even if they didn't they could get improved equality and compactness with a different combination of counties. The district court was quickly stayed by the Supreme Court, which heard the case and issued its ruling overturning the district court.
West Virginia conceded the first prong of the the test. But they used as their justification, that (1) the plan used whole counties; (2) that it only moved one county between districts, maintaining stability in representation; and (3) avoided pairing incumbents. The Supreme Court decided that these were legitimate state goals, and that the legislature's plan better achieved them than any of the alternatives.
The Supreme Court's ruling that the goals of the West Virginia legislature were legitimate, does not mean that they necessarily agreed with them, but were deferring to the judgment of the legislature, as they should.
