The name on everyone’s lips in Washington in one of the most talked about Senate races this fall is neither candidate. It’s Hasan Piker. He's been described as a left-wing “streamer from California.” For some progressives, he's part of the equation they argue the party needs to build a "winning coalition." To other Democrats and several Republicans, he's antisemitic and a “communist fanatic.”   Piker, who boasts 3.1 million followers...