IT IS RARE that a single scientific paper shapes how people think about a challenge as daunting as climate change. But one, known as “Wedges,” published 22 years ago by researchers at Princeton University, told an irresistible story. 

Lauren Davila made a stunning discovery as a graduate student at the College of Charleston: an ad for a slave auction larger than any historian had yet identified, Jennifer Berry Hawes reports.

The head of the Immigration and Customs Enforcement unit in charge of deportations has directed his officers to take action against all undocumented immigrants they may cross paths with, regardless of criminal histories. The guidance appears to go beyond the Trump administration’s publicly stated aims, and some advocates say may explain a marked increase in immigration arrests.