A day before the public hearing, an op-ed piece titled “Another ObamaCare Glitch” by Case Western Reserve University law professor Jonathan Adler and Michael F. Cannon, a health policy expert at the libertarian Cato Institute, appeared in the Wall Street Journal. They wrote that the IRS had no legal authority to give tax subsidies to people enrolling in a federal exchange. This argument became the foundation for the legal challenge to the law that is now coming before the Supreme Court.
More from that WPost article can be read here.
The think tank scholar mentioned above, Michael Cannon, is the Cato Institute's Director of Health Policy Studies.
Vox recently wrote a piece about him entitled "Meet Michael Cannon, the Man Who Could Bring Down Obamacare."
Here is a previous Think Tank Watch piece entitled "Conservative Think Tanks to Kill Obamacare?"
And here is a New York Times piece describing a presentation that lawyer Thomas Christina gave at the American Enterprise Institute (AEI) that helped bring about the Supreme Court challenge.