This week, the NPR Politics Podcast investigates defining moments in the lives of four top Democratic presidential candidates to understand how those experiences shape their politics today.Elizabeth Warren did not begin her professional career as a progressive firebrand. In the 1980s, she was a moderate-minded academic and law professor at the University of Texas, just beginning to her research into Americans who have declared bankruptcy.Over time, that work changed Warren and cultivated that kinds of progressive economic ideals that define her presidential run today.This episode: campaign correspondent Asma Khalid, campaign correspondent Scott Detrow, and White House correspondent Tamara Keith.Connect:Subscribe to the NPR Politics Podcast here.Email the show at nprpolitics@npr.org.Join the NPR Politics Podcast Facebook Group.Subscribe to the NPR Politics Newsletter.Find and support your local public radio station.