It is really weird to me that any Democrat thinks Sanders isn't a Democrat

[Jackpine Radical]

54. As Bernie uses the term, he's talking about a specific progressive

philosophical orientation.

Henry Wallace, FDR's first VP, was pretty much of the same stripe.

Wallace almost became the nation's president. In 1940, he was FDR's running mate and served as his vice president for four years. But in 1944, against the advice of the Democratic Party's progressives and liberals - including his wife Eleanor - FDR reluctantly allowed the party's conservative, pro-business and segregationist wing to replace Wallace with Sen. Harry Truman as the vice presidential candidate, a move that Stone calls the "greatest blunder" of Roosevelt's career. Had Wallace remained as vice president, he would have become president when FDR died in April 1945.

Wallace opposed the cold war, the arms race with the Soviet Union and racial segregation. He was a strong advocate of labor unions, national health insurance, public works jobs and women's equality. He would have been, without question, the most radical president in American history. He would have served out the remaining three years of FDR's fourth term and certainly would have sought to be elected on his own in 1948.

http://www.truth-out.org/opinion/item/14297-henry-wallace-americas-forgotten-visionary#