Whilst I agree that you in the US seem to have big problems with healthcare, you do also need to be aware of other issues, because these are certainly likely to be raised by those in favour of your healthcare system.
It will raise taxes, significantly - The amount of unmet demand has not yet been measured, and its not in the interest of anyone to do so, because if the antis did so then it would possibly demonstrate an urgent need for universal healthcare, and if the pros did it, this data could then be used to show just how expensive it would be in the first few years.
Unmet demand would swamp your system, you would end up with the worst of all worlds, because you would have to queue for medical treatment, costs would efinately rise far higher than originaly estimated, taxes would go up, and healthcare would become a political plaything.
When we in the UK set up our National Health Service, the amount of demand was wildly underestimated and as a result it took a couple of decades to get some sort of control.
Rationing, its not a nice word to use in the context of healthcare, but the fact is that when it comes out of the public purse the costs of some treatments versus their efficacy have to be balanced, do you spend $$$$$$ to keep one elderly person alive for one year, or spend the same on treating a child with luekaemia who may well only live the same length of time ?
Priorities, given that there is a large unmet demand and there is a finite amount of money to spend, someone will end up waiting for an operation, one surgeon can only do so much work, and this also depends upon things like blood supplies, availability of specialist nursing and physiotherapy, and possibly also home social workers to rehabilitate you, so that even if finance is available it takes years to train the staff needed to meet this demand - the queues will get longer.
on the other hand.
The whole raft of companies that thrive off the back of medical insurance in a privtely funded system leads to extra layers of cost, and in common with other forms of insurance such as in the motor vehicle market, there is always a huge incentive from the supplier of services to find ways to inflate the cost, and since all the insurer needs to do is raise premiums, there is are the control measures you would expect in private industry.
The costs of a medical episode in terms of the economy are not confined just to the patient, relatives will be involved, production may be lost until there is a return to work, which of itself raises issues of stand in staff, retraining etc.
Companies end up paying a large amount toward medical insurance directly, individuals may or not pay towards this, but in the end it places more of the burden fo such costs onto companies, whereas in the universal scheme, more of the cost comes out of taxes the individual pays.
Medical insurance contributes to labour force inflexibility, employees find it difficult to move from one employer to another due to the way many medical insurance contracts are arranged, it may be that you can’t overlap two policies, or that someone your policy covers in in the middle of a program of treatment which means effectively you can’t transfer to another employer who has a contract with a differant insurer.
Its grossly unjust, every person has a right to life, and every person has a right to the benefits of the fruits of the nation, why should someone who works plenty hard as a sewer worker not have access for themselves and their family when compared to, say, a highly paid computer programmer, do they not feel the same pain ?
In the UK we do have private medical care, its a tiny sector compared to the public system, but if you have the money then you can opt for it, it is not forbidden, but often, when complications arise from treatment and surgery, as happens in all medical practice, those same private patients are very often left to rely on the greater resources of the public system.
There are a large number of individuals and companies with ahuge interest in keeping US healthcare private, and to their end they have the influence and power to ensure that any problems in Nationalised Healthcare systems are widely publicised, but the mere fact that a significant percentage of your population has only access to emergency care and little else, and that so many bankrucies are because of medical costs - something that could happen to almost any American - should show you the lie to all this, think about the sums involved here, how much is 14% or your national budget ? An appreciation of such numbers would help you nderstand why there is a good deal of opposition to Nationalisation of US healthcare, a lot of people make a very large amount, they are not about to give up on that gravy train.