Supporters of the 1965 Immigration and Nationality Act pledged it wouldn’t radically change immigration. David Leonhardt, author of Ours Was the Shining Future, explains how it instead led to what might be the largest wave of immigration in human history. This episode was produced by Amanda Lewellyn, edited by Matt Collette, fact-checked by Laura Bullard, engineered by David Herman, and hosted by Sean Rameswaram. Transcript at vox.com/todayexplained Support Today, Explained by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices