Only one prominent Republican, Newt Gingrich, defended Bachmann, arguing that she and her colleagues were asking legitimate questions of the U.S. government.

That’s one case study. Here’s another:

Last week Sen. Harry Reid claimed in an interview that a Bain Capital investor told him Mitt Romney hadn’t paid taxes in 10 years. Reid passed along his similarly unfounded allegation with a striking admission: “Now, do I know that that’s true? Well, I’m not certain,” Reid said.

On Aug. 2, 15 days after McCain took to the Senate floor to defend Huma Abedin, Harry Reid stood in precisely the same spot and repeated his claim against Mitt Romney. To this day, not a single prominent Democrat has denounced him for it.