Video: Sen. Sanders' consistency
At 3:36 - Bernie Sanders: "To us what Socialism means basically is Democracy... it's the society in which you don't have a handful of giant banks and corporations controlling the economic and political life of a nation."
In other words, Bernie Sanders calls himself a "socialist" in the sense of someone helping society and not as it's economics meaning of turning over all modes of production to the State. As has been explained elsewhere, he's more in line with socialist democracies of Europe (think of the successful ones like Germany or Sweden).
The preamble to the Constitution says "We the people" not "we the corporations". In no way do the few people in a corporation represent all of America and in no way is allowing corporations to make national decision a constitutional act. The whole platform and approach of the GOP is unconstitutional in nature as it chooses few people over the many and even gives them personhood through big corporations which everyone has except the politicians, who as Trump accurately put it, are bought by people like the Koch Brothers. Sanders gets his money from the people and not some big donor or a small group of donors and has consistent policies and pass the test of being Constitutional. He is the closest thing we have to a Constitutional candidate (so far).
The type of socialism media, particularly Fox, is talking about is closer to communism where "the State controls all modes of production". The example Fox uses of socialism comes out to basic Christian charity, so I have to wonder what they are up to.
In more detail: An Overview Of How The GOP & Fox News Define "Socialism" by The Colbert Report (backed by news sources)