Real lefties does not include the Clintons,
Bill ruled as a centrist, Hillary is much more of a leftie.
the Obamas,
Are clearly on the left but had to adopt a more moderate platform in order to get anything passed in congress.
Bernie Sanders is certainly a real lefty in my opinion.
He defines himself as a socialist. are the only "true" lefties socialists in your view??
When you say "authoritarian" do you mean that he will be collecting more taxes in order to fund things like universal health care, social welfare?
Yes, all taxation is technically theft, therefore the only things worthy of government funding are those that justify the coercive hand of the state taking people's shit.
And trying to rein in the sort of extremes of the capitalist system that has led to things like the Global Financial Crisis?
Corporations own most governments, especially in the US; so this is in practical terms, impossible.
Hillary's leftist credentials pretty much rest entirely on being progressive on social issues. Both her and her husband are obviously very wealthy, have strong financial links and loyalties to the corporate sector, and are rightly perceived as being out of touch with the concerns of the growing precariat.
It's funny how if someone wanted to, for example, collect taxes to provide public housing for homeless veterans that would be classified by the political right as "authoritarian". But collecting $13 Billion to build a new aircraft carrier is not. Bernie Sanders is socialist in the sense that he wants to represent the 99% while Hillary was seen as a Washington DC insider who represented the wealthy while trying to "put lipstick on a pig" by being progressive on non-economic issues.
In terms of what I see as a "real leftist", it's someone who supports the interests of the working class and an increasingly less financially secure middle class over the interests of the wealthy and powerful. That tends to include "big government" items like social welfare, universal healthcare, public housing. Being socially progressive (fighting for the rights of minorities, etc.) has, in the past, tended to be secondary to that. Whereas many modern leftists appear to have completely skipped the economic side of the equation.
Socialist is a rubbery term that means pretty much whatever it suits someone for it to mean. Bernie Sanders took the path of owning that label rather than trying to argue around it, and good on him for that: it was a brave move IMO. He isn't, as far as I can tell, a socialist who supports nationalisation of private industry beyond what has been done in most of the developed world (universal healthcare, for example).