There's plenty to debate about the casino plans of the Federated Indians of Graton Rancheria.

Critics have asked legitimate questions about traffic and potential environmental impacts of a hotel and casino wedged between Rohnert Park and the Laguna de Santa Rosa. A federal judge is weighing arguments about constitutional issues involving the federal-state relationship.

But there's absolutely nothing legitimate about the latest opposition tactic: challenging the ancestry of Greg Sarris, the chairman of the Graton tribe and a leader of its successful effort to win federal recognition.

Marilee Montgomery of Rohnert Park asked the U.S. Interior Department, which oversees Indian tribes, to decertify Sarris, claiming that her review of census records determined that he isn't a Native American.

Montgomery is arguably the most prominent opponent of the casino plan — a plaintiff in the federal lawsuit, a spokesperson for a group called Stop the Casino 101 and a frequent contributor to these pages. She surely knows that, by federal law, tribal membership is determined by tribal members. And the Graton tribe has spoken clearly.

Montgomery's ersatz challenge only introduces ugly issues of race into a debate that should focus on public policy. This challenge should be withdrawn and replaced with an apology.