Bernie Sanders isn't perfect, but...
so wasn't FDR or Teddy Roosevelt.
Yes Teddy was a warmonger, but if it wasn't for him this country would probably be far more of a corporatist nightmare, with far less liberal influence than it is today (due to the success of the mega corporations in locking in power.) It took a man with chutzpah to take on the mega corporations of his time and save America from a corporatist nightmare. He also promoted conservationism, and expanded the role of the president, and was the most powerful influencer of FDR's life (to the point that it's not likely that FDR would've been president if it wasn't for Teddy's success.)
Yes FDR interned Japanese Americans (who should've at least been given prompt reparations payments, though FDR died before he could have the chance of doing so), but he prepared America for and successfully fought a world war (that would've been dangerous for America if Hitler won), enacted measures (including the GI bill and the top tax rates) that allowed the postwar boom wealth gains to be more equally distributed, creating the American middle class. Let alone saving the American economy from the worst of the great depression, and getting social security, unemployment benefits, minimum wage, overtime, child labor regulation, labor union protection laws passed, along with setting the example and carrying enough political momentum to get other presidents to be like him, including Truman, Eisenhower, and Johnson (who got civil rights, medicare, and medicaid passed.)
Bernie Sanders maybe is not "pure" enough to be a socialist, and maybe has his own skeletons in the closet (including support for Israel, unsupportive of gun control, and being more hawkish than an anti-war liberal) but he's still far more with the people than any other candidate, and the first one in a long time to have the chutzpah to take on the big corporations and the rich.
