Since the Supreme Court issued its opinion in Smith v. Bayer Corp., comity has become a more important doctrine to the class action world. Bayer, as you may recall, said that the denial of certification does not have a preclusive effect, but suggested that, instead, courts might use the doctrine of comity to reach the same result when plaintiffs’ counsel file repetitive class actions in the hope of winning certification in just one.

In the Seventh Circuit, Judge Posner quickly dashed that hope, pointing out that comity is also not a preclusive doctrine, which meant that courts were still free to exercise their discretion to hear copycat class actions.

Now, in Baker v. Home Depot USA, 2013 U.S. Dist. LEXIS 9377 (N.D. Ill. Jan. 24, 2013), a trial court in the Northern District of Illinois has resurrected a little hope that arguing comity may actually work.

Baker involved Home Depot’s use of wood treated with Chromium Copper Arsenate (CCA), a substance alleged to contain two known carcinogens. The use of CCA treated wood was discontinued in late 2002–except that the plaintiff alleged Home Depot continued to sell it until the end of 2003.

And, it turns out, various plaintiffs had been filing class actions since 2003 alleging the exact same facts against Home Depot. So Home Depot’s counsel filed a motion to dismiss, a motion to strike class allegations (which argued in part that comity required striking the allegations in this case), and a motion for sanctions. The court partially granted the motion to dismiss, denied the motion for sanctions, and granted the motion to strike class allegations. Its reasoning on the motion to strike:

In Smentek, the Seventh Circuit indicated that the denial of class certification in a materially similar case does not have a preclusive effect. However, the Seventh Circuit also indicated with respect to proposed class action litigation that, based upon the principle of comity, courts are required "to pay respectful attention to the decision of another judge in a materially identical case."

Home Depot has shown that the cases it has cited in its motion to strike are materially identical to the instant action. In those cases, the courts found that the named plaintiffs could not satisfy the commonality, typicality, and adequacy requirements of Rule 23(a), that individual issues of fact and law would predominate, and that a class action would not be manageable, nor the superior method for resolving the claims brought. … It is clear that many of the same problems identified by the courts in those cases with respect to class certification are similarly present in this case."

(Emphasis added.)  The takeaway for this case is pretty clear: be persistent. If a class action cannot work, most courts will respect prior opinions that have denied certification. And, of course, take class allegation seriously; you never know when plaintiffs will spend a decade chasing a class theory with obvious flaws.