In Casso v. Brand, 776 S.W.2d 551 (Tex. 1989), the Court held that neither the United States Constitution nor the Texas Constitution mandated a special summary judgment procedure in public-figure defamation cases. Casso, 776 S.W.2d at 555-57. The Court concluded that the United States Supreme Court's requirement that a plaintiff come forward with sufficient proof to allow a jury finding of actual malice by clear-and-convincing evidence was based merely on federal procedure. See Casso, 776 S.W.2d at 555-56. Although we recognized the importance of "encouraging free and untrammeled expression on matters of public concern or interest," we believed that the plaintiff's heavy burden of proving actual malice at trial adequately protected these important liberty interests. Id. at 557. To some extent, the Court based our holding in Casso on the different role of summary judgment in the Texas and federal systems. See id. at 556. At that time, our state's summary judgment practice served only the limited purpose of "eliminating patently unmeritorious claims and untenable defenses,'" id.