It's about money and power and who controls it. That's it, and that's all.
With money comes power, with power comes money.
That being said, do you want the power and the money in the hands of the people, or do you want the money and the power in the hands of the rich, corporate shareholders, and lobbyists?
It's really that simple.
If you lay out one issue after another, healthcare, welfare, foreign policy, people do agree on it about 70+% of the time. If you THEN labeled the results, the people would prefer a social democracy.
As for Bernie Sanders, I'm all in. Call me a communist (my family does) call me a socialist (i'm alright with that).
Just don't call me lacking understanding or empathy for humans or the earth we live on.
If you're interested in learning more, I suggest looking at each politician, their policy, and then their fundraising.