Sometimes when you cover politics it helps to have a bottle of Pepto-Bismol handy.

Some of the tactics of the McCain campaign have given me agita recently. But the latest campaign to turn my stomach was that of Nikki Tinker, a black woman who challenged a Jewish congressman, Steve Cohen, in a Democratic primary in Memphis.

Ms. Tinker was a candidate with nothing substantive to offer. A corporate lawyer, she was not particularly knowledgeable about Iraq or the economy or other important issues of the day. The raison d’être of her campaign seemed to be that she was an African-American running in a district in which the majority of the voters were also African-American.

And so she turned to the lowest tactics imaginable. In essence: let’s smear the white guy and get rid of him.

Mr. Cohen is seeking a second term. He is a reliably progressive congressman and an opponent of the Iraq war, and he has had a consistently solid record on civil rights. He was described by Speaker Nancy Pelosi as “the conscience of the freshman class.”