The Supreme Court ruled on President Obama’s healthcare law on Thursday, upholding the individual mandate as a tax in an opinion primarily authored by Chief Justice John Roberts.

In a significant distinction, the Court validated Congress’s power to pass the healthcare law under its taxing power—an argument that President Obama had downplayed because taxes are politically unpopular.

“Taxes that seek to influence conduct are nothing new,” the Court noted. Congress’s federal taxing power is generally wider and less contested than the commerce power, under Court precedent, so the ruling upholds the core of the healthcare law without pinning the opinion to limits on Congress’s commerce power.  (The Court did hold that the mandate would violate the Commerce Clause, but that did not resolve the case, since a majority of the Court upheld the mandate under the alternative taxing power.)

"The Government asks us to read the mandate not as ordering individuals to buy insurance," the Court explained, "but rather as imposing a tax on those who do not buy that product" (emphasis added). That distinction matters to the Constitution, the Court stressed, because Congress may reward people through taxes for actions that it might otherwise not be able to compel.  According to Justice Roberts’ opinion, the government does not endanger liberty as much when it makes policy through the tax code:

Although the breadth of Congress’s power to tax is greater than its power to regulate commerce, the taxing power does not give Congress the same degree of control over individual behavior (emphasis added). Once we recognize that Congress may regulate a particular decision under the Commerce Clause, the Federal Government can bring its full weight to bear. Congress may simply command individuals to do as it directs. An individual who disobeys may be subjected to criminal sanctions. Those sanctions can include not only fines and imprisonment, but all the attendant consequences of being branded a criminal: deprivation of otherwise protected civil rights, such as the right to bear arms or vote in elections; loss of employment opportunities; social stigma; and severe disabilities in other controversies, such as custody or immigration disputes.

While this ruling is huge political news, validating the largest domestic achievement of President Obama’s presidency, it does not significantly alter Supreme Court precedent or the powers reserved for the Congress.  For all the political attacks on the Affordable Health Care Act, a year ago, few legal scholars took the constitutional challenge seriously. Today’s opinion, joined by Chief Justice John Roberts, essentially endorses the current status quo, which enables Congress to use its taxing power to shape national policy and to incentivize certain behavior. It remains to be seen, however, whether the Court’s alternative approach to the law—which would have struck down the mandate under the Commerce Power—will be used later to limit Congress’s national power or curb progressive legislation.

The opinion is available here and The Nation is streaming live video coverage here. Lyle Denniston, an attorney who writes for SCOTUSblog, also provides this guide to reading the opinion.

This post has been updated.