Nina Totenberg for NPR:

But as Case Western Reserve law professor Jonathan Adler observes, “as odd as it may seem, federal judges are under no obligation to recuse in cases involving a prior benefactor, and there is no precedent for judges or justices recusing because the case implicates the interests of the president who nominated them.”

Technically, Supreme Court justices are not bound by the code of conduct in federal law, but they do try to abide by those rules. And as Adler, a conservative scholar, wrote this week, based on these criteria, Barrett may not be required to recuse. And yet, as he observed, there is another ground for recusal, namely, when a justice’s “impartiality might reasonably be questioned.” That, he suggests, may be why it would be “prudent” for Barrett to recuse. As he put it in a piece written for the Volokh Conspiracy blog:

“Trump’s own norm-breaking behavior may justify a departure from the traditional norms of recusal. His repeated comments about the role of courts in the election—and the Supreme Court and his nominee in particular—are [so] high-profile that they might create the sort of appearance problem that the recusal rules are designed to address. Simple prudence may counsel recusal in a special case like this. After all, we’ve never had a justice confirmed in the midst of an election before.”