An old white-supremacist idea haunts Trump's birthright citizenship case

Vox traces Trump’s birthright-citizenship challenge to a 19th‑century white supremacist argument popularized by lawyer Alexander Morse, who argued that citizenship should be denied to the children of foreigners transiently in the U.S. and, in practice, to Chinese Americans. Morse later abandoned the approach, and Wong Kim Ark settled the Citizenship Clause, but Trump’s brief echoes that old theory even as the constitutional text and Wong Kim Ark undermine it; the legal case against birthright citizenship remains strong.