Just some clarification of how healthcare works in the U.S. (I am a U.S. citizen living in UK but lived and worked in U.S. for 15 years). Healthcare is mostly offered by employers. I say mostly because you are usually required to work full-time, or 40 hours per week, in order to receive healthcare, which you still pay for as a deduction in your earnings. As a single woman, I was paying nearly $400 per month for employer-based health insurance. A family of 4 can pay as much as $2000 for health insurance.
And even with health insurance, you have to pay a co-payment to visit the doctor, for prescriptions, or any treatment you may require.
If your employment is under 40 hours per week, you will not even qualify for the company plan. So you will have to find insurance on your own if you want to have it. A lot of companies routinely offer 36-hour or 38-hour per week jobs so that they don't have to offer the healthcare benefit as it's expensive for businesses as well.
Once you are 65 years or older, you are eligible for Medicare, which is the government's healthcare program which is funded by federal taxpayer revenue. The idea is that you pay into it for your working life and then you can use it in your retirement. Some people with disabillities < 65 years old will qualify for this program, but not everyone. But even Medicare seems to be under threat.
If you are a college student and you graduate without a job (like so many), you would have had to get insurance on your own because you are over 21 years old. Obama's plan at least changed that so that these folks could stay on their parents' plans until they are 26.
Some states offer public health clinics which are funded by state tax revenue. My sister works in one of these in Florida as a paediatrician. Her appointment book is full until November.
Healthcare companies will often not insure people who have 'pre-existing conditions'--which can be anything. So people who have medical problems risk losing their coverage if they lose their employment or circumstances change.
If you are 'between jobs' or out of work, health insurance is an enormous expense. I always found it prohibitive and went without until I was in my next job. While very scary, I had to choose the ability to buy food and pay for shelter. Thank God nothing ever happened.
So many things need changing. But this is one of the biggest. Obama's just begun to transform the healthcare system. And the Supreme Court's verdict to uphold Obama's health insurance bill can easily be rescinded by the next President.