Here an excerpt from the abstract:
The question of what level of deference is owed legislative findings of fact (whether made by Congress or by state legislatures) in constitutional litigation is not a new one. It divided the Supreme Court in First Amendment cases in the 1920s, and again arose in the 1940s in the Japanese-American Internment case. In the modern era, however, and contrary to the position Solicitor General advanced in the above cases, the Supreme Court has consistently refused to defer to legislative findings regarding facts and mixed questions of law and fact where, as here, the resolution of such questions serves to define the scope of a fundamental constitutional right. Put differently, when legislation is subject to heightened scrutiny because it burdens a basic right, the Supreme Court has always engaged in a searching, independent review of constitutionally relevant factual findings and conclusions. This is not to say that legislatures may not make factual findings that affect the scope of rights, or that courts should ignore such findings when they exist. To the contrary, legislatures should be encouraged to make such findings, and when courts are faced with the obligation to determine constitutional facts upon which legislative findings are based, they should accord due respect to the legislature’s work. But judicial determinations of such facts should not be wholly deferential to legislative findings, nor are courts limited in their review to a record compiled by legislative bodies. Rather, courts must conduct an independent judicial review of legislative facts in constitutional cases and must remain free to gather and evaluate additional relevant facts, where they exist. A contrary rule would permit legislative bodies to evade and effectively overrule, through the guise of”fact-finding,”the most critical decisions of the Supreme Court, thereby undermining the Court’s preeminent role in constitutional interpretation mandated by Marbury v. Madison, 5 U.S. 137 (1803).
Downloadable here.
Read the other briefs in Gonzales v. Carhart.
Read the briefs in Gonzales v. Planned Parenthood.