Too many patients is the wrong way to look at it. But there will be too many "unfunded" patients, and there will be too many "overusing" patients. Think of it this way, people with private insurance may not abuse it because they still have to pay out of pocket expenses or deductibles or a combination of both, so when they go for services it will be during a time of definite need. By the nature of subsidized care, some will simply not care who's paying and use the services every time they have a stomach ache, nevermind it could have a perfectly logical explanation like eating too much spice, gas, overeating, hangover.....won't matter, they don't have to foot the bill, we do.
There will always be people who scurry to the doctor for every cramp and twinge... and there will always be others who stoically refuse to see a doctor- out of stubbornness or out of fear- no matter how serious their symptoms are.
People are diagnosed with stage 4 cancer every day.
By the time your cancer is stage 4, you've likely been living with pretty serious symptoms for years.
There will always be some who overuse doctors, and some who under-use them.
Those are basically the two sides of the hypochondriac coin (and I should know, because I'm a hypochondriac).
Either you go to the doctor constantly because you're afraid you're dying of a terrible disease... or you never go to the doctor, because you're afraid you're dying of a terrible disease.
Anyway, neither one of these categories comprise the majority of Americans.
Most people go to the doctor responsibly, for regular checkups and screenings or when they feel really sick.
As for the other two categories- people who go way too often and people who don't go nearly often enough- those people will do those things whether or not they're insured, because it's not money that's driving them; it's psychological issues.
Every ER in the country right now is full of people with sinus infections, bladder infections, sore throats, indigestion and heartburn.
People who over-use doctors will do so whether or not they're insured, whether or not they can ever pay.
Right now, ERs aren't allowed to turn them away, no matter how silly their complaints.
When these people have another alternative, perhaps ERs won't have to see them.