The debate over health care reform has been a theoretical affair, full of abstractions that contradict one another. Amid all the ambiguity, one fact is unequivocal and unprecedented.

Under the Patient Protection and Affordable Care Act, every American will be compelled to purchase health insurance, or else – the “or else” being a fine collected by the Internal Revenue Service should you fail to ante up.

“The mandate,” as it’s known, has its origins in the Commerce Clause of the Constitution, which grants Congress the authority to regulate interstate commerce. And yet it doesn’t take an Elena Kagan-level legal scholar (or even a fan of “Boston Legal” reruns) to see that the mandate, rather than regulating commerce, is this time being used to regulate the absence of commerce.

Why does that distinction matter? Well, at the risk of sounding alarmist, if Congress can compel the purchase of a product – health insurance – under its authority to regulate the interstate market for health care, then, using the same legal theory, what transaction can’t it compel?

Is it any wonder that likely voters reject the mandate by better than a 2-to-1 margin in most recent polling?

As just one example of the mandate’s potentially slippery slope, consider the interstate market for transportation. As we’ve seen with the $13 billion bailout of General Motors, stabilizing the automotive industry is clearly a Congressional concern. So why not compel Americans earning, say, more than $35,000 a year to buy GM cars? Or, better still, in a kill-two-birds tactic, why not compel them to buy Chevy Volts, thus ensuring the stability of the auto industry and the interstate market for clean energy?

As the federal government’s lawyers explained in a May motion in the Virginia Attorney General’s case against ObamaCare, “Foregoing health insurance … is not the same as foregoing health care. When accidents or illnesses inevitably occur, the uninsured still receive medical assistance, even if they cannot pay.”

Play out that logic: Those who get sick need care. People who need care drive up costs in the medical sector. Congress has the authority and the need to control medical costs. Thus, Congress can legally compel Americans to pay for health insurance.

If that’s a valid reading of the law justifying a mandate, then why not compel Americans to buy 24-Hour Fitness memberships or Nikes? The absence of exercise lowers your fitness level. That increases the likelihood you’ll need health care. Lather, rinse, repeat.

The government’s theory makes a case broad enough to control virtually all financial transactions – or the lack thereof. If such a mandate doesn’t offend you as a curtailing of liberty, then consider how likely it is to fail at its stated intention: Bringing 45 million Americans who today don’t have private health insurance or Medicaid into the risk pool, spreading out the risk across more payers and bringing down health insurance premiums.

That theory forms the foundation of Mass-Care, Massachusetts’ universal health care system passed in 2006. Unfortunately, Mass-Care and its mandate haven’t stopped spiraling health care costs. From 2007 to 2009 in the Bay State, the median annual premium for family plans jumped 10% to $14,300 a year. For small business, the increase was 12%. What’s worse is, Massachusetts already had the highest health care costs in the nation before Mass-Care became law.

Nor does the counter-intuition stop there. The ObamaCare debate often has focused on the $43 billion in uncompensated care bills racked up in 2008 by those without insurance (a number that represents less than 2% of the $2.5 trillion Americans spend on health care annually).

These costs have been attributed mostly to avoidable ER visits made by the uninsured. Make insurance mandatory, goes the explanation, and the ER onslaught will end. Fast forward to last week’s Boston Globe newspaper.

“The number of people visiting hospital emergency rooms has climbed in Massachusetts, despite the enactment of nearly universal health insurance that some hoped would reduce expensive emergency department use,” the paper wrote July 4th. “According to state data … emergency room visits rose by 9 percent from 2004 to 2008, to about 3 million visits a year.”

Mandatory insurance, it turns out, is not the same as access to a primary care physician. So even with the mandate, doctors are still in short supply, ER overcrowding continues and costs keep rising. Call it one more unintended consequence in the world of insurance made mandatory, a world many of us who support the Health Care Freedom acts – which already have become law in five states – are trying to avoid.

Not that everything is uncertain with this new law: America, you can rest assured, is badly in need of a new cliché. Now the only things certain in life are death and taxes – and the need to buy an insurance policy.

Dr. Eric Novack, a Phoenix orthopedic surgeon, is the chairman of the Arizona Health Care Freedom Act and the U.S. Health Care Freedom Coalition.

The views expressed by guest bloggers on the Foundry do not necessarily reflect the views of the Heritage Foundation.