NEWYou can now listen to Fox News articles! FIRST ON FOX: Before federal charges put ex-Southern Poverty Law Center (SPLC) official Heidi Beirich at the center of efforts to allegedly pay White supremacist informants, the left-wing Center for American Progress (CAP) hosted and praised her as an expert on extremism in the U.S. during a 2018 event.Neera Tanden, the CEO of CAP and a longtime Democratic operative who has worked for multiple Democratic presidents, including former President Joe Biden, described Beirich as among the "terrific leaders who are dedicating themselves to fighting the spread of extremism and speech online."The praise,...