Should the federal government be allowed to force a private citizen to purchase something?

The government already enforces mandates for insurance for items such as car insurance. This is because people can effect society at large with their activity with a car. Likewise, people effect society at large with their health. Untreated diseases and the uninsured using the ER as their general doctor have a negative impact on everyone. By mandating insurance so that everyone is covered, these problems are averted.