I think this is a good discussion, and it's sorely needed.
My impression is that the idea of court partisanship is largely a construction of everyone but the court. Don't get me wrong, the idea that judges are truly impartial is nonsense, but it's not really a case of partisan loyalty as it is the fact that we all have our biases.
For one, courts are often described as "allowing" the government to do something bad (or preventing the government from doing something good), but this is a somewhat misleading description. Sure, it's true in a literal sense, but it implies a much more policy-focused approach than is generally accurate. A good example is the case involving Amazon last year.
That case, Integrity Staffing Solutions v. Busk, was brought by employees (via a staffing agency) at an Amazon warehouse. They and all other warehouse employees were required to go through security after their shifts. They said that this could sometimes take a good 25 minutes, and argued that this was time that they should be paid under the federal Fair Labor Standards Act (FLSA). As relevant to this case, the FLSA says an employer does not have to compensate employees for any "activities which are preliminary or postliminary to [their] principal activity or activities, which occur either prior to the time on any particular workday at which such employee commences, or subsequent to the time on any particular workday at which he ceases, such principal activity or activities."
This idea of "principal activities," in turn, refers to both what someone's actual job duties are and anything that is required in order to get those things done. So for example, FLSA has been found to require a meat packer to compensate employees for the time they spend sharpening their knives, because dull knives would both affect the quality and quantity of the final product as well as be more likely to cause accidents. Mitchell v. King Packing Co., 350 U.S. 260 (1956). Another example comes from the Department of Labor's regulations, which is the case of an employee changing clothes prior to starting their actual work. If it's a requirement to do their job (such as an employee at a chemical plant putting on protective gear), that requires compensation. Otherwise, it doesn't.
With the Amazon workers, SCOTUS found that going through security screenings was not their primary job activity (which I don't think is controversial). Based on the law I quoted above, SCOTUS also found that the security screenings were not an integral part of the warehouse employees' jobs, since it wasn't something that they were required to do in order to be able to perform their work. After all, the screenings could've been done away with without any negative impact on employees' productivity.
That this is what the law was meant to do is obvious from its history. Back in 1946, the Supreme Court said that, in essence, employees had to be paid for "all time during which an employee is necessarily required to be on the employer's premises, on duty or at a prescribed workplace." Anderson v. Mt. Clemens Pottery Co., 328 U.S. 680, 690-691 (1946). In the 6 months following the decision in Anderson, some 1,500 lawsuits were filed against employers seeking $6 billion in back pay and damages. Congress quickly amended the FLSA to include the language described above.
I should add that the SCOTUS decision (regarding Amazon) was unanimous.
I largely agree with many of the criticisms of this outcome from a policy standpoint (this story from before the decision discusses this). But there's a difference between bad policy and bad law.
Thus I think we need to draw a better distinction between partisan appointments and partisan judges. Appointments were supposed to be political, which is why the President and Congress is involved. But that's the end of their influence, and is why it's virtually impossible to remove someone from the bench. You're never going to have a perfect system, but I do think the fears about court partisanship are overblown. And what's worse, they risk becoming a self-fulfilling prophecy. If Democrats or Republicans continue to criticize the court for making biased decisions, that will increasingly be its role in our society, since at the end of the day institutions are only valid insofar as we believe them to be.