Jonathan Gruber, the MIT economist, an “architect” of Obamacare, and the guy who stepped on so many land mines in his now famous videos, has an upcoming new role. Mr. Gruber is going to Capital Hill on Tuesday as a congressional witness to answer questions about all those things he said, like the “lack of transparency [about the law] is a huge political advantage” and why Gruber thinks voters are “stupid.”

Read here from Politico Magazine about the central issue in the latest Obamacare lawsuit to go before the Supreme Court. Gruber appears to be making the exact argument that the plaintiffs in the lawsuit are making: “If you’re a state and you don’t set up an exchange, that means your citizens don’t get their tax credits.”

As one of the lead attorneys in the case notes, “Gruber is Exhibit A that any English-speaking person knows what the subsidies language says.”

What really infuriates the Obama administration and congressional Democrats at the moment, however, is what Gruber said about the central issue in the latest Obamacare lawsuit to go before the Supreme Court: whether the law actually allows subsidies for people who get their health insurance through the federal marketplace that covers 37 states, not just people who get it from state-based marketplaces. If the justices decide that it doesn’t—thanks to the way one section of the law is worded—it can gut most of the law.

Just about every staffer who worked on the legislation says, no, that’s not what we meant—of course the law allows subsidies for everyone. But that’s not what Gruber said. In yet another video, from January 2012, he appears to make the exact same argument that the plaintiffs in the Supreme Court lawsuit are making: “If you’re a state and you don’t set up an exchange, that means your citizens don’t get their tax credits.” Naturally, the quote from that video is right there in the petition to the Supreme Court—which calls Gruber “one of the Act’s architects”—and it’s a good bet that it will come up in the oral arguments. Michael Carvin, the lead attorney in the case, sums it up: “Gruber is Exhibit A that any English-speaking person knows what the subsidies language says.”