[One of the more annoying pseudo arguments put against the Affordable Care Act runs along the lines of "We can't afford it!". Second runner up would be "Just keep using the emergency rooms." This attempts to address both points. I kinda like it, and thought I'd give you guys a chance to tell me how wrong I am. Thanks!]
Ask yourself this: Who currently pays for all uncovered, unsubsidized, unpaid medical expenses in the United States? We do. We the people. By indirect and complicated ways, we do. Every consumer of medical goods and services pays for every one that doesn't pay. With the federal government acting as financial backstop for emergency medical services, we all pay. And that's the way it is now.
What changes under the Affordable Care Act? One of the big things it does is pull these hidden expenses out into the daylight. With universal coverage, there should be no unpaid healthcare bills. Thus no need for hospitals to charge crazy fees that they then knock 95% off of if you have insurance. (The crazy numbers are just for heaping the costs up on people who don't have insurance and probably won't be able to pay their bill. By increasing the costs for these people, the hospital/medical service corporation gets to apply that inflated amount against their taxes. Bigger that number is, the more they get paid for "unpaid" medical care.)
The Affordable Care Act has changed this scheme and there should be far less "unpaid" care. However, part of this plan relies on individual states to participate by expanding Medicaid. States that don't will have the famous coverage gaps of too poor for Obamacare, too rich for Medicaid. These gaps are created by the inaction of the state legislature. Alabama has tens of thousands of people caught in this very gap, right now, for no better reason than the state legislature thinks punishing the citizens of Alabama communicates something important to the federal government. (Mostly it says some people are so hard headed they will hurt themselves before being seen to change their mind, but the federal government is well aware that there are people like that in the world.)
To a lesser degree, the federal Affordable Care Act also depends on the individual states not selling their citizens to an insurance monopoly. Competition keeps prices down, remember? But that's a story for another day.