Confirming recent speculation (also here) Justice John Paul Stevens will conclude 35 years on the Supreme Court bench, effective at the beginning of the Summer recess. And so the insider speculation about his replacement begins.

Stevens has been with employees, including public employees, for most of his career.  He is an avowed moderate, nominated by Gerald Ford and confirmed by a Democratic Senate.  He is the author of the most-cited opinion in the Court’s history (Chevron v. NRDC – all lawyers know this one).  His written opinions are pithy, concise (for a Supreme Court opinion, anyway), humble, and rigorously reasoned.  He was with public employees on overtime rights (Garcia) and on the First Amendment (GarcettiRankin, etc.).  And he has been with unions and all employees on issues like regulating workplace rights.

Obviously, the stances of Stevens’ replacement on fire fighter issues are crucial to ensure that fire fighter interests are preserved, particularly when the Roberts Court is showing hints that it is willing to pursue activist revisions of long-standing case law – to the detriment of viewpoints that have benefitted fire fighters for years.

If Stevens’ replacement takes the same stances that Stevens has taken, fire fighters can hope for the same, slim 5-to-4 majority that remains to preserve public employee overtime rights, maintain an expansive view of the commerce clause, uphold health and safety regulations, and protect public employees’ First Amendment rights to speech and association.

However, the departure of Stevens will be felt far more than the departure of Souter last year.

Stevens is the most senior Justice on the Court. Under Court rules, when the Chief Justice votes with the minority, the senior Justice in the majority is empowered to choose the author of a Court opinion.  In a frequently-split Court, Stevens was almost always the senior Justice on 5-to-4 votes.  It is believed that Stevens has been able to leverage this power either to write an opinion, or delegate the authorship of an opinion, in order to gain the fifth vote.  Since Sandra Day O’Connor’s departure that fifth vote has been Anthony Kennedy, and Stevens often used his power to move Kennedy into the “liberal” column on critical decisions by dangling the offer to write the opinion in front of him.

With Stevens’ departure, Antonin Scalia is the most senior Justice, which means very little, but the next most senior Justice is Kennedy himself – putting him in the driver’s seat even more than before.  (In descending order of seniority, following Kennedy, the next most senior Justices are Thomas, Ginsburg, Breyer, Roberts, Alito, and Sotomayor.)  In short, with Stevens’ departure, crucial pro-employee and pro-fire fighter decisions will be at the most vulnerable they have been in decades.

There is already rampant speculation of who President Barack Obama will nominate to replace Stevens.  The timing of Justice Stevens’ announcement (at the beginning of the term) means that the President and the Senate will have months to decide on the next Associate Justice.  We’ll keep an eye on that process as it moves through the summer.