The worst thing about Obamacare is not that the website doesn't work, nor that women (and men) in their fifties are required to buy policies with maternity and pediatric coverage, nor that the President out and out lied about how people could "keep" their coverage if they "like" it.
The worst thing about Obamacare is that private insurance companies are in charge, which, in many markets, means there is essentially, no competition. If only one or two companies want to get into a market (and why they're allowed to do it by county instead of by state is beyond me), premiums necessarily will be high. This is the state of affairs in many rural areas.
When Obama punked out on the public option, thinking he might get some "bipartisan" support (he didn't), he blew a hole in the side of "health care for all." If the Affordable Care Act is his "signature" achievement (along with strenuous persecution of whistleblowers), he's been a pretty crappy President.
It's unlikely the Democrats can take back the House in 2014, no matter how crazy the Tea Party has been and may be. Districts are too well gerrymandered. Even if they do, though, I don't think single payer would stand a chance. Robert Rubin Democrats will stand in its way.