You use an image of Che Guevara as the illustration to your post. However, since you are debating the concept or socialism in the terms presented by Bernie Sanders, perhaps it would be better suited, although less sensational, to use an image of the historic French socialist president François Mitterrand.
The use of the term “Socialist” by Bernie Sanders has been both provocative and educational. He has courageously shattered preconceived notions and intrigued Americans. Of course, he has been presenting contemporary western European ideas of Socialism and, more precisely, European Social Democracy — a doctrine that provided peace in Europe for more than half a century.
It makes no sense to question such Social-Democratic ideas based on definitions of Socialism that refer to Soviet-Socialism aka Communism — as Garry Kasparov recently did, in a very misleading and toxic way.
As others have said before, Bernie Sanders presents himself indeed as a Social Democrat. Social Democracy is a very simple notion of finding the right balance between private initiative economy and public interest services sustained by the State in key areas such as Health, Education or Justice. Social Democracy, or contemporary European socialism, has nothing to do with state control of sectors of production — or Che Guevara.