“Begging the question, sometimes known by its Latin name petitio principii (meaning assuming the initial point), is a logical fallacy in which the writer or speaker assumes the statement under examination to be true. In other words, begging the question involves using a premise to support itself. If the premise is questionable, then the argument is bad.”
Source: Begging the question (fallacy) – Grammarist
This is explained by example at a conservative leaning blog:
This insidious process of begging the question is typical of totalitarian propaganda which made abundant use of expressions like “undeniably”, “unquestionably” or as “everyone knows” or their more modern equivalents like as “all decent people agree …”, “the science is settled” or “this is not who we are” to assume what must otherwise be proved. But it nevertheless compels obedience like a herd driving itself along.
This has the effect of positing a consensus which in fact may not exist.
This is the basic concept of asserting something to be true, followed by asserting that everyone already agrees (“Get on the Bandwagon” propaganda method).
This propaganda statement is extremely common as illustrated by the last item, above “this is not who we are” – this statement, often in exactly those words – was issued by United Airlines after they assaulted a paying customer, was used by Equifax after losing personal data on 143 million Americans, and is used in almost every press statement after a company has been caught doing something wrong or just plain stupid. Yet empirically, this is exactly who they are as illustrated by the event they are responding to!
Statements such as “everyone agrees” are intended to anchor you to the thought that the discussion on the topic is settled.
Update:In late 2017, numerous entertainment, media and political leaders have been accused, often with numerous accusers and witnesses, of using their position of power to sexually assault or harass women. In almost every case, the accused has used the “this is now who I am” defense even when admitting to the behavior.
Sen. Al Franken’s resignation announcement text using the now traditional “this is not who I am” phrasing:
“I am proud that during my time the senate I have used my power to be a champion of women and that I have earned a reputation as someone who respects the women I work alongside everyday. I know there’s been a very different picture of me painted over the last few weeks, but I know who I really am,” Franken said on the U.S. Senate floor Thursday morning.