Dear Relative (Whose Name I’ll Withhold), You asked me tonight how the president’s promotion of public preschool could in any way lead to more moms staying home with their kids. I want to answer that question. But first, let’s back up. This video has been circulating in the past day, as you know: In the video, Obama is quoted as saying: “Sometimes, someone, usually mom, leaves the workplace to stay home with the kids, which then leaves her earning a lower wage for the rest of her life as a result. And that’s not a choice we want Americans to make.” The willful misreading of this quote should be embarrassing to us, because it’s such concrete evidence of our national reading comprehension crisis, but…