06/28/2012 04:45 pm ET Updated Aug 28, 2012

All Hail the Sixteenth Amendment!

The survival of ObamaCare and the individual mandate ultimately came down not to the Commerce Clause, but to the Sixteen Amendment, the one that clearly gives Congress the power to enforce federal power through the tax code.

While the dissenting four Justices sought to make a constitutional distinction over the fact that the Affordable Care Act used the word "penalty" rather than the word "tax," Chief Justice John Roberts chose common sense over semantics. If a law increases your taxes because of something you did or did not do, it is a tax provision just like the thousands of other tax rules that exist that reward and punish people for doing things -- and for not doing things.

This is a simple and straightforward defense of the Obamacare law, yet defense of the individual mandate as a valid and constitutional tax was remarkably muted, both in opinion pages and in the briefs filed by those supporting the law. It was there, but tucked into back pages and paragraphs.

Progressives tend to valorize the Commerce Clause as the root of progressive federal power, but that tendency is an accidental product of history. A rightwing Supreme Court after the Civil War struck down a range of civil rights laws then, saying the Fourteenth Amendment did not give the federal government the power to stop private segregation. So when the modern civil rights movement fought for new civil rights legislation, they did it in the name of the Commerce Clause, not the Fourteenth Amendment.

But really, it is the Sixteenth Amendment that is one of the purest products of mobilization by progressives. In 1895, another rightwing Supreme Court -- there were so many of them -- struck down an income tax law passed by Congress the year as unconstitutional. Years of grassroots organizing led in 1913 to passage of the Sixteenth Amendment and it was on that scaffolding that progressive taxation to fund the modern welfare state was possible.

Step back and remember that the creation of a national income tax was the rallying cry of a generation of progressive activists and thinkers. Yet, many liberals today are gun-shy in talking about the progressive role of taxes, largely because of anti-tax conservative rhetoric. But progressives need to recover the populist language that understands that taxes increase the welfare of working families. Taxes transfer money from the wealthy and unproductive activities (or lack of activity such as refusing to buy health insurance) to help families in need and promote activities that support the general welfare.

Some legal advocates are wringing their hands that some potential limits on the Commerce Law were validated in Chief Justice Roberts' opinion, but what his opinion also made clear is that the taxing power is and remains the royal road to progressive regulation of the economy. Liberal reluctance to utter the word "tax" in the language of the Affordable Care Act almost torpedoed the law based on the semantics of "taxes" versus "penalties," so the lesson of the case should be to use the word "tax" proudly when it's deployed on behalf of improving our nation.

So all hail the Sixteenth Amendment and the progressive movement that led to its passage, which in turn made Obamacare's victory at the Supreme Court possible.