Justice Alito’s opinion for the Supreme Court in the Harris v. Quinn case gives all kinds of reasons for overturning the key pro-union case of Abood. Yet the Court majority does not pull the trigger. Why not? This seems to be a common move of the Roberts Court, as I explained in Anticipatory Overrulings, Invitations, Time Bombs, and Inadvertence: How Supreme Court Justices Move the Law, 61 Emory Law Journal 779 (2012): “Anticipatory overruling occurs when the Court does not overrule precedent but suggests its intention to do so in a future case.” It is one of the tools the Roberts Court uses to appear moderate and minimalist.
For example, the Court did not immediately overturn the preclearance provision of the Voting Rights Act when it had the opportunity to do so in the 2009 NAMUDNO case. Instead it signaled the Act was unconstitutional, and then overturned it in the 2013 Shelby County case. As I’ve explained, the Court in Shelby County relied upon dicta in NAMUDNO as though that earlier case had settled it. Similarly, on the campaign finance side, Chief Justice Roberts and Justice Alito signalled the coming overruling of the ban on corporate general treasury spending in elections in the Wisconsin Right to Life case, and then pulled the trigger with the 3 other conservative Justices in Citizens United.
But just because the Court takes two or three cases to reach its highly ideological decision doesn’t make it any less ideological or any more comporting with principles of judicial minimalism or respect for precedent.