It shouldn't be the government and the taxpaying population to pay for an individuals lack of personal responsibility. Most medical problems are preventable by personal responsibility, and most medical problems can be treated by getting insurance. If you can't be responsible for your own health, or you don't pay to get healthcare, noone else should have to pay for it. The Government exists to protect against external threats and to enforce legal contracts, period. It does not exist to protect people against themselves, it's asinine to think that it's a magical entity than can fix any problem. If you're dying of cancer in a hospital due to your 3 pack a day habit, that's your own fault. There's no reason the government, which is funded by taxes, to pay for that. The Constitution guarantees the rights to life, liberty, and the pursuit of property, changed to happiness. Nowhere does it mention health, or wealth, or power. Everyone is in control for the most part of their own destiny, it's not the burden of the state to heal people who can't provide for themselves.
And honestly, have you ever waited in line at the DMV, or the Post Office? These are the people that will be in charge of the health care system. They get a government paycheck, they get very generous retirement, and they have the protection of the federal government. It's a bad idea. Universal healthcare will raise the cost of healthcare to the people already paying for it, who deserve it, and raise the cost to employers to offer it. If you can't afford it, you don't get it. Even in healthcare, it's not a universal guarantee, and it shouldn't be. A person shouldn't expect society to bear their burden.