It's a stupid argument in the first place. If there was a social healthcare system in the US, then do rich people somehow have less money? Do people really believe that there won't be better 'cutting edge' techniques that are expensive, but you can only pay for 'out of pocket' or with a private insurance company?

It's not like private insurance doesn't exist in Canada (for example). You're just guaranteed a certain base-level of medical care by the government. You still have to pay for things like prescriptions unless you have private insurance. Things -- like dental work -- are not covered either unless you have private insurance plan that covers it.

{edit} You have to pay for non-life threatening prescriptions, like anti-depressants or antibiotics. Just thought that I should clarify that IIRC, things like insulin which a person needs to stay alive are covered by the government {/edit}