( CNN ) -- This week , the U.S. Supreme Court considers the case challenging the Obama administration health care plan 's requirement that most Americans purchase a government-approved health insurance plan by 2014 . The court should rule that this individual mandate is unconstitutional . To do otherwise would give Congress almost unlimited power . The federal government argues that three provisions of the Constitution -- the commerce clause , the tax clause and the `` necessary and proper '' clause -- authorize the health care mandate . The commerce clause gives Congress authority to regulate interstate commerce . Since the 1930s , Supreme Court decisions have interpreted the commerce clause broadly . But every previous case expanding the commerce power involved some sort of `` economic activity , '' such as operating a business or consuming a product . Failure to purchase health insurance is neither commerce nor an interstate activity . Indeed , it is the absence of commerce . If Congress could use that clause to regulate mere failure to buy a product on the grounds that such inaction has an economic effect , there would be no structural limits to its power . Any decision to do anything is necessarily a decision not to do something else that might have an economic effect . If I spend an hour sleeping , I thereby choose not to spend it working or shopping . As the lower court decision in this case explained , the government 's position `` amounts to an argument that the mere fact of an individual 's existence substantially affects interstate commerce , and therefore Congress may regulate them at every point of their life . '' Read a transcript of Monday 's Supreme Court arguments . Defenders of the insurance mandate claim that health care is a special case because everyone eventually uses it . But this argument relies on shifting the focus from health insurance to health care . A similar rhetorical ploy can justify any other mandate , including even the `` broccoli purchase mandate . '' Not everyone eats broccoli . But everyone participates in the market for food . Similarly , a mandate requiring all Americans to purchase a car can be justified because virtually everyone participates in the transportation market . The government also claims that health care is different because producers are sometimes required to give free emergency services to the uninsured . But why is this fact constitutionally relevant ? The answer seems to be that failure to buy insurance thereby has adverse economic effects on producers . Put that way , failure to buy health insurance turns out to be no different from failure to buy any other product . Any time someone fails to purchase any product , producer profits are lower than they would be otherwise . The government 's tax-clause argument is similarly flawed . It asserts that the individual mandate is n't really a restriction on freedom , it 's just a tax ; violators are forced to pay a fine . If this logic is correct , it would justify any mandate enforced by a monetary fine , whether it be for broccoli , a car or anything else . Every lower court to have considered this constitutional issue has ruled that the mandate is not a tax but a penalty . As President Barack Obama acknowledged in 2009 , `` for us to say that you 've got to take a responsibility to get health insurance is absolutely not a tax increase . '' Finally , the government relies on the clause that gives Congress the power to `` make all Laws which shall be necessary and proper for carrying into Execution '' other powers the Constitution grants it . The federal government argues that the insurance mandate is a `` necessary '' element of its regulation of the health care market under the commerce clause . The court has previously defined `` necessary '' broadly as anything that might be `` useful '' or `` convenient . '' But even if the mandate is necessary , it is not `` proper . '' The court has previously ruled that these are two separate requirements and both must be met . What makes a federal law `` proper '' ? At the very least , a proper law can not depend on a rationale that gives Congress virtually unlimited power . As James Madison said : `` Whatever meaning this clause may have , none can be admitted that would give an unlimited discretion to Congress . '' If the `` necessary and proper '' clause allows Congress to adopt the individual mandate , the same logic would justify almost any other mandate . Virtually every mandate has some economic effect and could be portrayed as a `` useful or convenient '' way to regulate some market . A broccoli mandate could be defended as an effort to regulate the market in food . The threat to liberty raised by this case is n't just theoretical . Many industries would be happy to lobby for laws requiring people to buy their products , and Congress has a long history of enacting special-interest legislation . In a recent decision , the Supreme Court unanimously emphasized that constitutional constraints on federal power protect state rights as well as `` the liberty of the individual . '' Little will be left of that protection if the justices uphold the individual mandate . The opinions expressed in this commentary are solely those of Ilya Somin .
Ilya Somin says Supreme Court should find Obama health care plan unconstitutional . He says the law is a "massive expansion of federal power over state and local governments" that will lead to more government control over people's lives. He argues tax-clause argument also a problem , saying failure to insure brings penalty , not a tax . Somin : Necessary and proper argument could allow Congress to justify any mandate .