Professor Steven Pinker thinks it all came down to the placement of an adverb:
... 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.
Though the ungrammaticality of split verbs is an urban legend, it found its way into The Texas Law Review Manual on Style, which is the arbiter of usage for many law review journals. James Lindgren, a critic of the manual, has found that many lawyers have “internalized the bogus rule so that they actually believe that a split verb should be avoided,” adding, “The Invasion of the Body Snatchers has succeeded so well that many can no longer distinguish alien speech from native speech.”
In his legal opinions, Chief Justice Roberts has altered quotations to conform to his notions of grammaticality, as when he excised the “ain’t” from Bob Dylan’s line “When you ain’t got nothing, you got nothing to lose.” On Tuesday his inner copy editor overrode any instincts toward strict constructionism and unilaterally amended the Constitution by moving the adverb “faithfully” away from the verb.
President Obama, whose attention to language is obvious in his speeches and writings, smiled at the chief justice’s hypercorrection, then gamely repeated it. Let’s hope that during the next four years he will always challenge dogma and boldly lead the nation in new directions.