Michael Ramsey, one of the leading scholars/defenders of originalism, has a post on Rucho at The Originalism Blog that offers a distinct assessment of the decision. Critics of Rucho will like the first half of his analysis, but not the bottom line.
On the Court’s justiciability holding, Ramsey writes:
I’m entirely unpersuaded. Courts routinely draw difficult lines between borderline-acceptable behavior and borderline-unacceptable behavior. True, this is often messy. Justice Scalia, for example, famously wanted bright lines and hated balancing tests. But if the lack of a bright line makes a claim nonjusticiable, federal courts are going to have a great reduction in work load.
To take a couple of examples favored by center-right originalists, it’s not so easy to say when a law is sufficiently necessary and proper to the regulation of interstate commerce that it falls within Congress’ enumerated powers. Few people doubt that some federal regulation of local matters is justified due to their connection to interstate commerce, but how much connection is enough? This question isn’t considered a political question, nor should it be. And to take a very recent case, any re-invigoration of the nondelegation doctrine, as suggested by Gundy v. United States, involves deciding how much policymaking delegation by Congress is too much (it being undoubtedly true that some policymaking delegation is inevitable). It’s true that Justice Scalia thought this was sufficient reason to hold nondelegation claims basically nonjusticiable, but the current Court (including Chief Justice Roberts) seems prepared to reconsider. In neither of these situations (nor in many others I can think of) does the Constitution say exactly where the line should be drawn. But, generally speaking, courts still decide these cases, perhaps with a good bit of deference to the government in the gray areas. As I think a famous Justice said, the existence of twilight does not mean we cannot distinguish day and night.
The Court in Rucho does better in noting two points: (1) that founding-era Americans knew about partisan gerrymandering; and (2) that they nonetheless generally gave state legislatures power over districting, subject to oversight by Congress, but not subject to any other express limitations. One might say that this builds a case for application of the other prong of the political question doctrine — that a constitutional judgment is textually committed to another branch. But I doubt that approach as well. The fact that Congress has oversight does not mean the courts do not also have oversight.
Instead, I think the Court’s points about the text and history show something different: the Constitution does not limit partisan districting. At minimum, I would say that the originalist case for a constitutional limit on partisan districting is not proved. That does not mean partisan districting isn’t bad. It well be, as Erwin Chemerinsky argues here in commenting on the Rucho case (and quoting Justice Scalia) that it is “incompatibl[e] … democratic principles.” But the Constitution does not enact “democratic principles” in the abstract. And it does not have a provision governing districting, although it could have. Put this way, districting is a political question, but not because of some arcane doctrine of justiciability. It is a political question because the Constitution did not address it, and thereby left it (like many other issues) to the political branches.