Rev. Al Sharpton’s National Action Network has received millions of dollars from prominent labor unions whose bosses frequently appear on the controversial activist’s MSNBC show, often without any disclosure about their lucrative financial ties. In the past year alone, Sharpton, who hosts PoliticsNation on the weekends, has interviewed the presidents of five unions that have given his nonprofit a total of $6.3 million: American Federation of Teachers, National Education Association (NEA),