Excerpts from Chief Justice Roberts' opinion on healthcare reform Today we resolve constitutional challenges to two provi­sions of the Patient Protection and Affordable Care Act of 2010: the individual mandate, which requires individuals to purchase a health insurance policy providing a mini­mum level of coverage; and the Medicaid expansion, which gives funds to the States on the condition that they pro­vide specified health care to all citizens whose income falls below a certain threshold. We do not consider whether the Act embodies sound policies. That judgment is entrusted to the Nation's elected leaders. We ask only whether Congress has the power under the Constitution to enact the challenged provisions. In our federal system, the National Government pos­sesses only limited powers; the States and the people retain the remainder. Nearly two centuries ago, Chief Justice Marshall observed that "the question respecting the extent of the powers actually granted" to the Federal Government "is perpetually arising, and will probably continue to arise, as long as our system shall exist." In this case we must again determine whether the Constitution grants Congress powers it now asserts, but which many States and individuals believe it does not possess. Resolv­ing this controversy requires us to examine both the limits of the Government's power, and our own limited role in policing those boundaries. Today, the restrictions on government power foremost in many Americans" minds are likely to be affirmative pro­hibitions, such as contained in the Bill of Rights. These affirmative prohibitions come into play, however, only where the Government possesses authority to act in the first place. If no enumerated power authorizes Congress to pass a certain law, that law may not be enacted, even if it would not violate any of the express prohibitions in the Bill of Rights or elsewhere in the Constitution. Indeed, the Constitution did not initially include a Bill of Rights at least partly because the Framers felt the enu­meration of powers sufficed to restrain the Government. As Alexander Hamilton put it, "the Constitution is itself, in every rational sense, and to every useful purpose, A BILL OF RIGHTS." And when the Bill of Rights was ratified, it made express what the enumeration of powers neces­sarily implied: "The powers not delegated to the United States by the Constitution . . . are reserved to the States respectively, or to the people." The Federal Government has expanded dramatically over the past two centuries, but it still must show that a consti­tutional grant of power authorizes each of its actions. The same does not apply to the States, because the Con­stitution is not the source of their power. The Consti­tution may restrict state governments - as it does, for example, by forbidding them to deny any person the equal protection of the laws. But where such prohibitions do not apply, state governments do not need constitutional au­thorization to act. The States thus can and do perform many of the vital functions of modern government - punishing street crime, running public schools, and zoning property for development, to name but a few - even though the Constitution's text does not authorize any government to do so. Our cases refer to this general power of govern­ing, possessed by the States but not by the Federal Gov­ernment, as the "police power." This case concerns two powers that the Constitution does grant the Federal Government, but which must be read carefully to avoid creating a general federal authority akin to the police power. The Constitution authorizes Congress to "regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes."Art. Our precedents read that to mean that Congress may regulate "the channels of interstate com­merce," "persons or things in interstate commerce," and "those activities that substantially affect interstate com­merce." The power over activities that substantially affect interstate commerce can be expansive. That power has been held to authorize federal regulation of such seem­ingly local matters as a farmer's decision to grow wheat for himself and his livestock, and a loan shark's extor­tionate collections from a neighborhood butcher shop. Congress may also "lay and collect Taxes, Duties, Im­posts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States." U. S. Const., Art. Put simply, Con­gress may tax and spend. This grant gives the Federal Government considerable influence even in areas where it cannot directly regulate. The Federal Government may enact a tax on an activity that it cannot authorize, forbid, or otherwise control. The reach of the Federal Government's enumerated powers is broader still because the Constitution authorizes Congress to "make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers."Art. We have long read this provision to give Congress great latitude in exercising its powers: "Let the end be legitimate, let it be within the scope of the constitu­tion, and all means which are appropriate, which are plainly adapted to that end, which are not prohibited, but consist with the letter and spirit of the constitution, are constitutional." Our permissive reading of these powers is explained in part by a general reticence to invalidate the acts of the Nation's elected leaders. "Proper respect for a co-ordinate branch of the government" requires that we strike down an Act of Congress only if "the lack of constitutional authority to pass [the] act in question is clearly demon­strated." Members of this Court are vested with the authority to interpret the law; we possess neither the expertise nor the prerogative to make policy judgments. Those decisions are entrusted to our Nation's elected leaders, who can be thrown out of office if the people disagree with them. It is not our job to protect the people from the consequences of their political choices. Our deference in matters of policy cannot, however, become abdication in matters of law. The powers of the legislature are defined and limited; and that those limits may not be mistaken, or forgotten, the constitution is written. Our respect for Congress's policy judgments thus can never extend so far as to disavow restraints on federal power that the Constitution carefully constructed. The peculiar circumstances of the moment may render a measure more or less wise, but cannot render it more or less constitutional. And there can be no question that it is the responsibility of this Court to en­force the limits on federal power by striking down acts of Congress that transgress those limits. The questions before us must be considered against the background of these basic principles. The individual mandate requires most Americans to maintain "minimum essential" health insurance coverage.26 U. S. C. §5000A. The mandate does not apply to some individuals, such as prisoners and undocumented aliens.§5000A (d). Many individuals will receive the required cov­erage through their employer, or from a government pro­gram such as Medicaid or Medicare. See §5000A (f). But for individuals who are not exempt and do not receive health insurance through a third party, the means of satisfying the requirement is to purchase insurance from a private company. Beginning in 2014, those who do not comply with the mandate must make a "[s]hared responsibility payment" to the Federal Government. §5000A (b) (1). That payment, which the Act describes as a "penalty," is calculated as a percentage of household income, subject to a floor based on a specified dollar amount and a ceiling based on the aver­age annual premium the individual would have to pay for qualifying private health insurance. §5000A (c). In 2016, for example, the penalty will be 2.5 percent of an individ­ual's household income, but no less than $695 and no more than the average yearly premium for insurance that co­vers 60 percent of the cost of 10 specified services (e.g., prescription drugs and hospitalization). The Act provides that the penalty will be paid to the Internal Revenue Service with an individual's taxes, and "shall be assessed and collected in the same manner" as tax penalties, such as the penalty for claiming too large an income tax refund. The Act, however, bars the IRS from using several of its nor­mal enforcement tools, such as criminal prosecutions and levies. §5000A (g) (2). And some individuals who are sub­ject to the mandate are nonetheless exempt from the penalty - for example, those with income below a certainthreshold and members of Indian tribes. §5000A (e). The Government's first argument is that the individual mandate is a valid exercise of Congress's power under the Commerce Clause and the Necessary and Proper Clause. According to the Government, the health care market is characterized by a significant cost-shifting problem. Every­one will eventually need health care at a time and to an extent they cannot predict, but if they do not have insur­ance, they often will not be able to pay for it. Because state and federal laws nonetheless require hospitals to provide a certain degree of care to individuals without regard to their ability to pay, see, e.g., 42 U. S. C. §1395dd; Fla. Stat. Ann. §395.1041, hospitals end up receiving compensation for only a portion of the services they pro­vide. To recoup the losses, hospitals pass on the cost to insurers through higher rates, and insurers, in turn, pass on the cost to policy holders in the form of higher pre­miums. Congress estimated that the cost of uncompen­sated care raises family health insurance premiums, on average, by over $1,000 per year. In the Affordable Care Act, Congress addressed the problem of those who cannot obtain insurance coverage because of preexisting conditions or other health issues. It did so through the Act's "guaranteed-issue" and "community- rating" provisions. These provisions together prohibit in­surance companies from denying coverage to those with such conditions or charging unhealthy individuals higher premiums than healthy individuals. See §§300gg, 300gg-1, 300gg-3, 300gg-4. The guaranteed-issue and community-rating reforms do not, however, address the issue of healthy individuals who choose not to purchase insurance to cover potential healthcare needs. In fact, the reforms sharply exacerbate that problem, by providing an incentive for individuals to delay purchasing health insurance until they become sick, rely­ing on the promise of guaranteed and affordable coverage.