First of all, I’m personally opposed to trying to do a statistical analysis of votes, for the legislature or the courts.
For the courts in particular, the majority of cases they have to deal with are not going to fit neatly into what precedent the Democrats or Republicans appointed them with the goal of setting/changing/maintaining. Even for those that do, sometimes the cases are just out of left field or they don’t fit into the exact precedent a justice wants to be able to set. And sometimes you get “politically apolitical” strategic votes like Roberts has at time made. Examples of this would be dissenting when it’s not the deciding vote, while you may have joined the majority if it mattered, or agreeing to switch and vote in exchanged for a compromised ruling.
I know this isn’t a very satisfying answer, but you have to make a best guess at how justices on each side want to set/alter precedent on a particular issue, see how consistently a majority opinion alters precedent, and how closely divided those votes are. Of course this is entirely guesswork. It’s basically a certainty that none of the justices (OK maybe Alito ) want to establish legal precedent in a way as simple as some voters do (i.e. just make abortion legal/illegal in all cases), so actually trying to figure out how they want to set precedent is going to have to be an educated guess.
Also for the Trump appointees, it’s definitely going to take years to draw any conclusions about them other than what any of us already thinks about the Roberts court.
It was kind of a joke, a lame one, I guess, but it typically wouldn’t be Democrats who say that women don’t have the temperament to be a justice, and I doubt the Republicans would say that about one of their own who they are slamming through the process before an election.
“Qualifications” are part of the theater, like the pointless hearings. It’s a part-time political patronage job, but part of the mystique is the idea that the court is some grand temple of thought where only the brightest lights can be admitted. The Senate, long under the spell of similar delusions about itself, is happy to play along.
That particular photograph should be a cautionary tale. Had LBJ been slightly more circumspect in who he appointed, the balance of the court might be different today. Abe Fortas was forced to resign from the court after just three and a half years, and his failed nomination for chief justice ended up giving both seats to Nixon appointees. Nixon ended up bungling one of those seats by trying to appoint two different segregationists (both were rejected by the Senate) and his eventual choice ended up being far more liberal than was expected (Ketanji Brown Jackson has been nominated for that exact seat).