This Letter to the Editor originally appeared in the Politico on October 28, 2009.

My Oct. 20 column in POLITICO (“Making Individuals Buy Insurance Is Unconstitutional”) explained why Obamacare’s individual mandate is unconstitutional. Erwin Chemerinsky then wrote a rebuttal Oct. 23 (“Health Care Reform Is Constitutional”), claiming to explain how I was wrong.

Like Harold Koh, Cass Sunstein and Elena Kagan, Chemerinsky is renowned both as a legal scholar and as an unapologetic liberal. Many on the left would like to see him on the Supreme Court.

But despite his brilliance, his rebuttal suffers from a fatal flaw: Somehow he completely misses both of my points and never refutes them.

First, he says Supreme Court precedent allows Congress to regulate anything with a “substantial effect” on interstate commerce. True, but irrelevant.

Every Commerce Clause case requires an economic action by an individual. Then the question arises whether it’s interstate commerce that Congress can regulate. But here, government would regulate and penalize inaction; it’s people not buying insurance. They never engage in any act for Congress to regulate.

In 2000, the court struck down the Violence Against Women Act. The reason? It didn’t involve an economic action. Same problem with Obamacare.

Second, he says the mandate penalty could be a tax because the court upholds any tax that’s reasonable. Also true but also irrelevant.

The Constitution still requires federal taxes to be a capitation, excise or income tax. The reasonableness requirement means it must be a reasonable capitation, reasonable excise or reasonable income tax. The Obamacare mandate penalty is none of those three. That’s why it can’t be a tax.

I thank Chemerinsky for giving a serious response to my column, even though he’s incorrect. After my column ran, a reporter asked House Speaker Nancy Pelosi which constitutional provision authorized Congress to impose this individual mandate. The speaker replied, “Are you serious?” and refused to answer.

Yes, Madame Speaker, I’m serious.

The individual mandate is unconstitutional. If Obamacare passes, we’ll see you in court.