a patient governor (or staffer) could totally change a provision by hunting for the appropriate letters

It gets worse (better?): in a computerized world, patience is irrelevant. Suppose we have a letter-item veto on Title I of the U. S. Code, and we think it would be better if, instead of all those boring "general provisions" and "rules of construction", this document codified into law P. C. Hodgell's maxim that "That which can be destroyed by the truth, should be." Then, casting a spell like this---

#!/usr/python3
title1 = open("Title_01.txt").read()
target = "That which can be destroyed by the truth, should be."
target = list(target)
target.reverse()
keep_chars = []
for i, c in enumerate(title1):
....try:
........if c == target[-1]:
............keep_chars.append(i)
............target.pop()
....except:
........break
print(keep_chars)
revised = ""
for i in keep_chars:
....revised += title1[i]
print(revised)

---we learn that all we have to do is veto all characters except the fourth, 408th, 409th, 502nd, 510th, 705th, 894th, 895th, 936th, (more numbers redacted ...), and 8786th.