The linguistic norm for any language in the world that has a standard (usually set by academies or by traditional ascription to a prestigious social group) is subject to change over time like any other aspect of human behavior. We all aspire to speak like our fellows––specifically, members of our own community, starting with our immediate family and working outward as we grow older and come in contact with a widening circle of individuals.
What speakers conceive of as the norm is variable and fluid. No sane person whose native language is American English would normally (i. e., excepting a jocular intent) say something like “It is I” in answer to a question instead of “It’s me,” even though the subjective case of the personal pronoun is traditionally required after the copula (and may have been inculcated by old-fashioned teachers). On the other hand, older speakers may still adhere to “whom” rather than “who” with pre- and postpositions (cf. “To whom did you give it?” vs. “Who did you give it to?”). The drift of the language is clear, in any event: the colloquial has been replacing the formal as a general trend for some time.
When the norm is violated by speakers who have great prestige, even the fact of the solecism’s perception as such may not deter other speakers from imitating the mistake. A recent example is President Barack Obama’s use of the catachrestic “good-paying job” (instead of the correct “well-paying job” [explained in an earlier post, “Semantic Contamination,” July 22, 2009]) in a speech on the economy broadcast two days ago. Within a speaker’s lifetime the choice of linguistic variant may change, of course: Mr. Obama may have adhered to the norm at an earlier stage of his life and adopted the contemporary (incorrect) form under subcutaneous pressure to sound “like one’s fellows.” Whatever the biographical facts in this case, the prestige of a public figure’s office and of his persona typically works to give powerful impetus to the perpetuation and spread of an innovation––no matter how erroneous––among speakers whose admiration for a model overrides linguistic probity.