I have written this piece for Reuters Opinion.  It begins:

Will Justice Anthony Kennedy’s support for a constitutional right to gay marriage doom the constitutionality of affirmative action and a key provision of the Voting Rights Act?  To answer this question, legal scholars need to know less about constitutional law and more about human psychology.

Consider  last year, when Supreme Court Chief Justice John Roberts, for example, surprisingly sided with the court’s four liberal members in upholding President Barack Obama’s healthcare law against constitutional challenge. It was a stunning choice for the conservative jurist. The reaction of Nate Persily, a leading U.S. election law scholar, was: “There goes the Voting Rights Act.”

At first, the connection between the two cases may seem tenuous. They don’t involve the same issues. The healthcare case was based on Congress’s power to regulate commerce and to tax. In Shelby County v. Holder, heard last month and expected to be decided in June, the court is considering whether Congress’s power to enforce equal rights, especially in voting, includes the power to continue federal oversight of elections in certain states that have a history of racial discrimination.

But Persily’s observation seems correct, and it illustrates how Supreme Court watchers often use amateur psychoanalysis of the justices. For example, a chief justice, feeling constrained by public opinion or concerned about the court’s legacy, may give in on one case in order to gain more political capital to spend on another controversial case.