Truth: The case in question was Pioneer Hi-Bred International v. J.E.M Ag Supply and involved a Monsanto competitor. Monsanto was not a party to that case.

Clarence Thomas worked for Monsanto for a few years but has not been employed by Monsanto since the 1970s, long before the company was involved in biotechnology or owned a seed business.

The Supreme Court’s decision in Pioneer v. J.E.M. upheld the ruling of the appeals and lower court decisions that plants are indeed subject to patent protection under U.S. patent law. The Supreme Court agreed with both lower courts.

While Justice Thomas indeed wrote the majority opinion, this was a 6-2 decision. Justice Thomas was joined by Chief Justice Rehnquist, and Justices Scalia, Kennedy, Souter and Ginsberg – none of whom have or had any association with Monsanto. Justices Breyer and Stevens dissented, and Justice O’Connor did not participate in the decision.

In short, while one former Monsanto employee was involved in a Supreme Court case to which Monsanto was not a party, the decision in that case merely confirmed the substantial prior case law and U.S. Patent Office precedent to the effect that plants are subject to patent protection under U.S. law.