I think there will be a divide between support for a strong public option and full on single payer. I don't think the system or the country is ready for single payer. The ACA only really deals with individual market and single payer would be dealing with employer sponsored plans + individual market.
This is why I don't think single payer will ever happen in the US. Once suburban/middle-class Americans learn that a single payer may up end them from their plans, then the politicians will quickly jump ship.
The justifiable concern is that after their employer is no longer providing them with a health insurance plan worth $10,000 a year, they won't be getting a $10,000 raise to even things out. (And then they'll have to have their taxes raised to fund single payer.) They're worried it would basically amount to a pay cut for people who get insurance through their job.
