Bernie Sanders returned $470 from the only billionaire who donated to his campaign

Sen. Bernie Sanders (I-Vt.) has made it clear his 2020 campaign isn't funded by billionaires. Except for a little while, it was. Marta Thoma Hall, the wife of a billionaire inventor, gave $470 to Sanders' campaign this summer -- and when Sanders' team realized, they promptly returned it, Forbes reports. Hall's husband David Hall, who "doesn't have as much of an interest in politics," holds a patent on a self-driving car sensor, and his stake in the Velodyne company has recently been valued at ov...