In interpreting a constitution, justice is best carried out when the justices are non-partisan rather than politically ideological. To be sure, every living and breathing human being has a political ideology, even if implicitly. Even so, the institutional process by which justices are chosen can mitigate this point by being oriented to non-partisan candidates. In other words, a system can be designed so as to minimize the likelihood that a partisan of one political party or another will sit on a constitutional court. The confirmation of Neil Gorsuch to sit on the U.S. Supreme Court can provide some insights in this regard.
The full essay is at "How to Craft a Non-Partisan Court."
The U.S. Senate's Judiciary Committee meeting on Gorsuch's nomination on April 3, 2017. (NYT)