Last week, the U.S. Department of Justice announced that it would not prosecute users of medical marijuana in states where it is legal. The Obama administration deserves credit for removing the federal government from the private decisions of individuals. It should extend this principle to the ongoing debate over health care reform.

An individual’s decisions about his health are some of the most difficult, personal, and consequential ones he will make. A right to privacy in sexual and reproductive matters has long been recognized and accepted; a similar respect should be given to the choices made by doctors and patients as to the best means of treating the patients’ illnesses.

Although no health care bill has been officially presented, it’s becoming more and more clear that the leaders of both houses of Congress intend for the federal government to play a huge role in the health care industry. If, as appears likely, health care reform includes a public option, then the government may very well become the sole provider of health insurance. Should that happen, a government bureaucracy would get to choose what ailments get covered, just as private companies do now. But unlike now, if the public plan became a monopoly and you didn’t like the care you were receiving, you could not switch plans. There would be nothing you could do.

Liberals argue that this won’t happen. They say the public plan would only be one option and, rather than crowd out private providers, would spur them to greater efficiency through tough competition. They may be right.

But for that to happen, the government would have to let the private providers compete. It would have to resist giving subsidies or other legal advantages to the public plan. The public plan would have to face the creative destruction of the marketplace; if it ran consistent deficits, the government would have to let it fail rather than use taxpayer money to bail it out.

If, as is more likely, the government uses its tremendous power to give the public plan an unfair advantage, the public plan would be able to offer artificially low prices and more and more Americans would switch their coverage. Then they’d be at the mercy, not of the profit motive, but of the one motive more selfish: the political one.

The government would get to decide which people deserve which coverage. It would get to determine which procedures to pay for. It would play a huge role in deciding what your doctor can and can’t do for you.

Due to the nature of our political system, powerful constituencies would get better coverage. Difficult decisions involving controversial practices, like abortion, would be made, not by a doctor and her patient but by the government bureaucrat charged with rationing care. That bureaucrat, along with the agency he works for, would be subject to political pressure from the Congress and the White House. Health care would become political.

Allowing states to make their own laws regarding medical marijuana is an encouraging sign that the Obama administration understands the importance of privacy in medical matters. But if the federal government becomes the arbiter of who deserves what medical coverage, it will be a moot point. When you get sick, it will be you, your doctor, and Uncle Sam in the consulting room.