How far can Congress probe the judicial thought process?

Over at the Volokh Conspiracy, Josh Blackman has a fascinating post (really, a series of posts) about the efforts of ten Democratic Senators to force two Eleventh Circuit judges to “explain” their involvement in Florida’s felon disenfranchisement cases.

The brief background is this: the Florida Supreme Court heard oral argument on a challenge to state legislation conditioning the restoration of a convicted felon’s right to vote on the payment of legal financial obligations. Two of the Justices on the court at the time, Robert Luck and Barbara Lagoa, had been nominated for seats on the Eleventh Circuit Court of Appeals. Both Justices asked questions during oral argument, but were confirmed to the Eleventh Circuit just weeks later. Accordingly, neither Justice had any role in the outcome of the case.

On July 15 the plaintiffs, having sought review in federal court, requested that both judges recuse themselves from the Eleventh Circuit’s deliberations. The request was grounded on the fact that the judges had merely asked questions during oral argument while on the Florida Supreme Court, even though they had taken no part in the decision. (This was factually reminiscent of the Ninth Circuit case of Yovino v. Rizo, involving a judge who had voted on a case but died before it was announced; here, however, the judges did not vote at all.)

Professor Blackman had a very sensible take whether recusal was necessary in the Eleventh Circuit case:

Judges are allowed to change their views. And that malleability is a good thing. I would be troubled if judges walked into arguments with a set predisposition, that could not be disturbed.

Yovino¬†demonstrates that a Judge’s questions during oral arguments, and even a conference vote, are not “immutable.” Judges are allowed to keep an open mind till late in the game. These preliminary matters are not enough to question a judge’s impartiality. The only decision that counts is the final order. Judges Luck and Lagoa did not participate in the Florida Supreme Court’s published decision. Therefore, they are not disqualified.

But it’s 2020, and legal arguments aren’t good enough for the political class. Hence, the subpoenas. Blackman’s take (which you should read in its entirety) concludes:

I have serious doubts about whether Congress has the power to subpoena a judge to testify about internal judicial matters. I think Congress could justify that subpoena as part of an impeachment inquiry. But a general need for information to craft legislation would not be suitable.

I am not a constitutional scholar, but that strikes me as correct.