The Republican debate on Fox News on Thursday night was an argument over whose was bigger. Whose lies. Whose poll numbers. Whose ... wherever.

A gobsmacking day of intraparty pie-throwing ended with Donald J. Trump, from the stage of the Fox Theater in Detroit, assuring the American public that the size of his male appendage was just fine. “I guarantee you,” he said, “there’s no problem.”

There was a time when I might have been stunned. There was a time when Mr. Trump kept his anatomical allusions to post-debate interviews, when he referred to the moderator Megyn Kelly — who was tough on him at his last debate on Fox, in August — as having “blood coming out of her wherever.”

I might have been shocked, once, at this whole debate — the hooting audience, the barking candidates, the NSFW content — but those days are over. The memory is already fading. This is our life now.