In Gibson v. American Cyanamid Co., 760 F.3d 600 (7th Cir. 2014) (No. 10-3814), the Seventh Circuit addressed a constitutional challenge to Wisconsin’s common law Risk-Contribution Theory.  The Risk-Contribution Theory, adopted by the Wisconsin Supreme Court in Thomas v. Mallet, 701 N.W. 2d 523 (Wis. 2005), provides that a plaintiff suing for damages based on exposure to lead paint who cannot ascertain the manufacturer of the specific paint used may sue all of the industry leaders.  Where a plaintiff establishes that his or her injuries result from exposure to lead paint, the burden shifts to the defendant-manufacturers to prove that they did not manufacture the paint to which the plaintiff was exposed.  Those who fail to establish that defense become liable.  The Seventh Circuit concluded that the Risk-Contribution Theory comports with due process requirements because its relaxed causation standard effectuates a rational state goal of having the lead paint manufacturers share the costs of injuries caused by their product rather than leaving innocent injured plaintiffs uncompensated.  The court also held that a recently-enacted Wisconsin statute that eliminates the Risk-Contribution Theory in pending and future court cases violated due process in this case, which already was pending when the legislature enacted this statute, because the plaintiff had a vested right in his claims under the Theory.