I have written this post for a Balkinization symposium on a terrific new book by Devins & Baum,  The Company They Keep: How Partisan Divisions Came to the Supreme Court (Oxford University Press, 2019). My post begins:

In an eye-opening 2013 interview with journalist Jennifer Senior, the late Supreme Court Justice Antonin Scalia explained his “media diet.” He said that he read the Wall Street Journal and the Washington Times. He had dropped his subscription to the Washington Post because of what he saw as the newspaper’s “treatment of almost any conservative issue. It was slanted and often nasty. And, you know, why should I get upset every morning? I don’t think I’m the only one. I think they lost subscriptions partly because they became so shrilly, shrilly liberal.” He also said he did not read the New York Times and that he got most of his news from talk radio.

Scalia’s media diet was a sign of things to come.

In Neal Devin’s and Larry Baum’s indispensable new book, The Company They Keep: How Partisan Divisions Came to the Supreme Court, the authors convincingly argue that the two leading political science models of Supreme Court judicial decisionmaking—the attitudinalist model positing that Justices vote their values and the strategic model positing that Justices vote strategically to advance their values in light of the potential reactions of other strategic actors, such as Congress and executive agencies—inadequately describe the Justices’ decisionmaking. Devins and Baum offer a psychological model positing that Justices, like others, are the product of the world around them, and Supreme Court Justices travelling in elite social circles seek affirmation and approval from these elites.

In an earlier era, a common social circle of other judges, law professors, lawyers, at the top of the profession and journalists at elite news outlets helped shape the Justices’ values and occasionally rein in their votes, and that given an historic liberal bent of the legal elite (at least on civil rights and civil liberties issues), many Justices “evolved” over time toward the left on these issues. The authors write of the so-called “Greenhouse effect” where even some conservative Justices were swayed by coverage of the Court and its decisions by the New York Times’s former Supreme Court reporter, Linda Greenhouse.

But polarization has changed everything on the Supreme Court. Thanks to polarization in Congress and the Presidency, for the first time in Supreme Court history all of the conservative-leaning Justices have been appointed by Presidents of one party and all the liberal-leaning Justices appointed by Presidents of the other party. The most conservative Democratic-appointed Justice is more liberal than the most liberal Republican-appointed Justice.

As Devins and Baum argue, today’s politically polarized elite world both shapes and reflects how Justices view their jobs and decide how to vote, leading to a new polarization on the Supreme Court. Adam Bonica and Maya Sen’s work confirms that the leftward drift of lawyers overall is accelerating, giving plenty of affirmation for the liberal Justices on the Court. At the same time, the ascendancy of conservatives and libertarians in the Federalist Society has created an alternative set of elite actors to whom conservative Justices on the Supreme Court can look for ideas, law clerks, and social affirmation. Lower court judges brought up from Federalist Society ranks appointed by Republican Presidents frequently advance theories which would have been  to use Jack’s term, “off the wall” in an earlier era, and reinforce one another as to the legitimacy of these new views….