Coburn was one of the original authors of the federal Partial-Birth Abortion Ban Act upheld by the United States Supreme Court in "Gonzales v. Carhart". The act relied on an expansive view of the Constitution's Commerce Clause, as it applies to "any physician who, in or affecting interstate or foreign commerce, knowingly performs a partial-birth abortion." The Act's reliance on such a broad reading of the Commerce Clause was criticized by Independence Institute scholar David Kopel and University of Tennessee law professor Glenn Reynolds, who noted that "nless a physician is operating a mobile abortion clinic on the Metroliner, it is not really possible to perform an abortion 'in or affecting interstate or foreign commerce.'" When Coburn later called Supreme Court nominee Elena Kagan "ignorant" due to her "very expansive view" of the Commerce Clause, his support for the Act was used by Kagan supporters who charged him with hypocrisy on the issue.