This is not one of those blogs where I pose a question and then answer it; I honestly don't know the answer to this and I'm look for some feedback on the matter.
My full question is this, if the Congress were to pass a bill that offered subsidies for low income people to buy private care, eliminated the preexisting conditions problems and made it illegal to drop coverage of sick people; how would premiums and overall costs come down or even stay flat?  
I would imagine that helping people who don't currently have insurance go to a regular doctors office rather than the emergency room will help; but how much?
Obviously the insurance companies aren't going to take these limitations in how they can "save money" out of their ability to make a profit; so won't they have to increase premiums to pay for actually covering all of there clients through to the end?
I am an advocate of the Public Option, but I'm hoping that someone could explain how we might control costs without a large new competitor.