Could a judge be charged with perjury for breaking a promise made during a confirmation hearing?

Lessig suggests no.

Chiafalo v. Washington involved the so-called "faithless electors." During the arguments, Justice Gorsuch asked Larry Lessig, if a faithless elector could be charged with perjury for violating a sworn oath:

JUSTICE GORSUCH: Counsel, could a State, for example, ask an elector to make a sworn statement as to his present intention to vote for a particular candidate, make the pledge an oath?

MR. LESSIG: Yes.

JUSTICE GORSUCH: And could a State later prosecute that elector for perjury if that statement under oath --if there's evidence that that was a false statement?

I chuckled at Lessig's answer:

MR. LESSIG: In principle, absolutely, Your Honor. We think, in practice, that would be just like with a Judge making a promise to a Senate committee upon confirmation --prior to a confirmation, it would be incredibly difficult to imagine enforcing in a way that wouldn't just be retaliatory against a particular elector.

In other words, a perjury prosecution would really be a pretext for a vote the judge cast.

Remember, promises made to Susan Collins are not enforceable.