You have to consider as well that SCOTUS justices are lifetime political appointees. There is definitely a trend in their opinions toward the same end of the spectrum as the President who nominated them. See https://en.wikipedia.org/wiki/Ideological_leanings_of_United...
SCOTUS being constructed out of political motivation does not, in itself, make the members of SCOTUS themselves motivated by politics. Having a belief system is inherent to human nature, and SCOTUS does not select their own members. The political motivation is exclusively a part of the selection process.
And you are missing mine. Given that they are political appointees, and their ideology reflects that of the appointing president, it is reasonable to suspect that they, in fact, are politically motivated.
I suppose if we wanted to figure this out, we could just ask the Federalist Society what they think.
It is reasonable to suspect SCOTUS hopefuls are politically motivated before appointment.
After appointment, there is nothing to be motivated for. They hold the highest possible position in their career path and political support or approval no longer bears any utility.
It doesn't matter what they say -- evidence demonstrates that SCOTUS members throughout history have been consistently observed to vote with their established ideological preferences.
That's correct. they vote to advance their own political agendas. Those agendas also correspond to those of the appointing President's party. That's literally the definition of "politically motivated." The available evidence thus points toward individual Justices being politically motivated. Occam's razor suggests the burden of proof falls more strongly on the opposite position.
The available evidence, and scholarly consensus, shows they vote based on their established personal ideologies. If you are claiming it is more complicated than this, Occam's Razor is on you.
They get more liberal overtime as well. The court is partisan. Even the current. You can look at 5-4 and majority decisions and there are tons of flip flopping by different justices.
That's correct. The court is partisan and the general trend for each justice is toward the more liberal. Note, however, that in the diagrams contained in the linked wiki article, no justice who starts above 0 (the "conservative" area) ever dips below 0 into liberal territory. Conservatives stay conservative and liberals get more liberal.
Having an ideological preference is not the same thing as being partisan, nor is it evidence thereof. These are different things.
Someone can be partisan and not have an ideological preference. (eg. party employees, pandering politicians)
Someone can have an ideological preference and not be partisan. (eg. religious leaders, philosophers)
If you want to demonstrate that SCOTUS members are partisan, you need demonstrate they voted for the a party's preferences instead of their own ideological preference. If you are instead demonstrating that they voted in line with their own ideological preference, you are simply pointing out that humans have belief systems.
