Bernie Sanders nabs his first Senate endorsement

In the midst of an intensifying debate over the role of so-called superdelegates in the Democratic presidential primary and their outsized support for Hillary Clinton over Bernie Sanders, the Vermont senator has picked up another superdelegate and, most remarkably, his first endorsement from a sitting U.S. senator.Oregon's Jeff Merkley announced his endorsement of Sanders in a New York Times op-ed published Tuesday evening. The liberal Democrat, who is not up for reelection this year, is th