I love the narrative that the longest independant on the senate, which by itself is an amazing accomplishment that speaks of his record, is one of the most effective members of the senate to pass progressive amendments is a hack that doesn't know anything that he is doing.
He wants single payer because he wants the state to be able to negotiate drug prices because they're absurdly expensive. They can be up to 1000% more expensive compared to Canada. The privatized system is still insanely expensive for the state, in which the USA pays the most per capita on health care and doesn't have the benefits for the people. As head of the veteran health stuff in the senate he passed the most progressive health aid system for the veterans, which I believe is completely government ran.
I will say this, in his website he cites Chile as a country that's gonna start offering free college this year but it has been an absolute disaster. The country was incredibly mobilized in 2011 and up to 2013 for quality affordable college and the new government promised it because they are corrupt populists (still better than the right mind you) and tried to pass the law in like a month after assuming command. It went on for a year because the budget was horribly mismanaged, they had a horrible new tax plan that affected medium/large enterprises that slowed business to a crawl and at the end of the day they got free tuition for 200.000 students I believe.
On the other side of the coin, I wish hillary would stop being disingenuous and stop lying about NY gun epidemic, singling Vermont as a key problem. 1% of the guns that come out of state are from Vermont and is a non issue and even a super delegate for Clinton called her out and said "election times makes people exaggerate and misrepresent issues".