The Supreme Court did not hear arguments directly relating to the merits of the individual mandate yesterday, but the skepticism many of the justices did voice suggests that when the Court does reach a decision on the merits, they will reject one key Obama administration defense of the law.

At issue Monday was whether Obamacare’s individual mandate was a tax pursuant to the Anti-Injunction Act. If it is, then all federal courts would be barred from hearing a challenge to the law until the first American is forced to pay the tax in 2015. But even the most liberal justices on the court seemed skeptical of this argument.