… is from pages 12-13 of Randy Barnett’s and Evan Bernick’s important 2021 book, The Original Meaning of the Fourteenth Amendment: Its Letter and Spirit (footnotes deleted):
Why good-faith construction? Upon taking their Article VI oath to adhere to the Constitution, all constitutional actors receive a great deal of discretionary power. With this power comes a corresponding normative obligation to implement the Constitution in good faith in a way that is analogous to the duty that private law imposes on “fiduciaries.” Fiduciaries are power-exercising parties who have been delegated control over resources belonging to other (think attorneys, agents, and boards of directors). Similarly, to fulfill their duty, judges and legislators must act consistently with the letter of the instrument from which they draw their power. They also must not abuse their delegated powers by using whatever discretion that original meaning gives them to pursue their own extralegal ends, goals, purposes, or objects, rather than serving the interests of their principals. Where the letter of the Constitution is unclear, fidelity to the Constitution’s design requires that judges, legislators, and other constitutional decision-makers turn to the law’s original spirit.