Of the three days of U.S. Supreme Court hearings devoted to the federal health care reform law, Commentary‘s Jonathan S. Tobin labels today’s session as the most important.

[T]he main event will be on Tuesday, as the question of whether the Commerce clause of the Constitution can be interpreted in such a manner as to allow the government to require Americans to engage in commerce rather than to merely regulate it is debated.

For most liberals, including President Obama and the Democratic majority in Congress that rammed this law down the throats of an unwilling people two years ago, the notion that there are any such limits on the power of the federal government is laughable. To be fair to them, they do have much of the history of 20th century American politics on their side. During the last century, Washington’s power has expanded to the point where there is almost nothing that can be imagined that can’t be justified by the Commerce clause. That’s why this case is so important. Barring an electoral revolution this November in which Republicans sweep both Houses of Congress and the White House, we will have lost our last chance to preserve our freedom.