In a video published on May 10, 2016, Cenk Uygur of The Young Turks says that Hillary Clinton has the worst favoribility rating in Democrat history, according to a recent Gallup Poll. Her favorability rating last Fall was 63. By April it had dropped markedly to 36.
In a graph shown on the video, Hillary's trend since September was shown to be in a general decline, while Bernie Sander's general trend has been upward. In fact, the graph shows them almost switching places by March.
Gallup, well respected as an unbiased and objective polling company, notes that Bernie Sanders "reached his personal net favorable rating apogee (+63) in late March/early April, and although it's been down slightly since then, he is still the most positive rating for any candidate of either party at this point, by a large margin."