I don't know what you consider middle-class but paying $20, 30, 40k+ for a college education is a walk in the park only for those making well into six figures. I'm talking $200k a year and up. And that's top 10% of all earners.
And no, it doesn't do anything for the lack good-paying jobs but it does make life easier. I mean, a recent graduate making a shitty $30k/year is going to live a lot better if he has 0 college debt (or just a couple thousand, let's say) than if he has that same $30k/year job but also a $50k loan to repay.
Finally, it's been well-researched that single-payer would cost a bunch, yes, but it would save even more, resulting in a net gain.
http://www.pnhp.org/news/2013/august/study-single-payer-healthcare-system-would-save-billions