The main question before the Supreme Court in terms of the constitutionality of the Affordable Care Act (Obamacare) is whether the federal government has the power to mandate that American citizens purchase a product or service offered by a private company. This question needs some explanation. Part of the separation of powers in our governmental design is the concept of federalism. One aspect of federalism is the balance concerning what powers the state governments have over its citizens and the power that the federal government also has over citizens. The states may be able to have an individual mandate to buy health insurance, but the federal government may not have that power. It has been accepted that individual states can order citizens to purchase health insurance as seen in Romneycare in Massachusetts. The question before the court is whether the federal government can order every American to purchase health insurance.
Some have wrongly compared this to the requirement for all Americans to be part of social security or medicare. These programs are based on the power of the federal government to tax, which is established as constitutional. Another difference between those programs and the private insurance mandate is that social security and medicare are both administered by the federal government and are not private products or services. That the federal government has the power to pass laws that cause people to be taxed and can administer those programs has been established. The question before the Supreme Court is whether the federal government can require citizens to purchase a private product or service. Interestingly enough, had Congress passed and the president signed a program that taxed people for a new government-run, single-payer system, the constitutionality of that would probably not be in question. The new national health program would have been based on the power of the federal government to tax and administer the program. This would have passed constitutional muster and would have been seen as being similar to social security and medicare. The majority in Congress, along with President Obama, chose to require individuals to purchase insurance from private companies and this created the issue of whether the individual mandate is constitutional. Whether the federal government has the authority to require each person to purchase a private product and service is what makes it a constitutional question.
Some have also wrongly compared this is to the mandates to purchase auto insurance coverage. One difference is that auto insurance is done on a state level and not a federal level. Driving is a privilege and not a right, so each state can have requirements that extend to those who wish to own automobiles due to the inherent possibilities of injury to oneself or to others. Additionally, if one chooses not to own an automobile, there is no requirement to have insurance, which is unlike the federal requirement for all Americans to have health insurance. If this is found to be constitutional, then theoretically, the federal government could require all its citizens to purchase all sorts of products like cell phones, computers, bicycles, and internet service.