[dem bums]

Demoting Roberts would not end his tenure on the bench . . . just his place on that bench.

The "office" that Roberts holds is "Chief Justice of the United States." Demoting him to "Associate Justice of the United States" (a separate office) would end his tenure in this office, and would thus require impeachment.

[Pilgrim's Progress]

Then a fair question might be . . . would a truly conservative congress impeach him? Also, as I understand it a president can still be impeached even after his term of office thereby stripping him of his pension and benefits.

However the operative phrase is . . . “truly conservative congress”