I was saying this in an email just last week. Glad the Toimes caught up with me in theorizing that the Chief Justice flubbed to oath because he doesn’t understand English grammar:
Language pedants hew to an oral tradition of shibboleths that have no basis in logic or style, that have been defied by great writers for centuries, and that have been disavowed by every thoughtful usage manual. Nonetheless, they refuse to go away, perpetuated by the Gotcha! Gang and meekly obeyed by insecure writers.
Among these fetishes is the prohibition against “split verbs,” in which an adverb comes between an infinitive marker like “to,” or an auxiliary like “will,” and the main verb of the sentence. According to this superstition, Captain Kirk made a grammatical error when he declared that the five-year mission of the starship Enterprise was “to boldly go where no man has gone before”; it should have been “to go boldly.” Likewise, Dolly Parton should not have declared that “I will always love you” but “I always will love you” or “I will love you always.”
Any speaker who has not been brainwashed by the split-verb myth can sense that these corrections go against the rhythm and logic of English phrasing. The myth originated centuries ago in a thick-witted analogy to Latin, in which it is impossible to split an infinitive because it consists of a single word, like dicere, “to say.” But in English, infinitives like “to go” and future-tense forms like “will go” are two words, not one, and there is not the slightest reason to interdict adverbs from the position between them.
Not all he doesn’t understand either.