"I'm not convinced that single payer would be any worse than what went on prior to ACA".

And that's the bottom line isn't it? BTW they didn't do it the first time because they didn't even have enough Democrats to vote for single payer. 
I have been voting since 1968 and if you would like to see how the country has changed over the years this might be interesting reading. You might not like the site but feel free to do your own research after reading it. 
http://www.dcclothesline.com/2017/07/14/10-secrets-about-america-that-will-make-you-wonder-where-all-the-freedom-went/