No he isn't. Unlike you, Marshall is well aware of the rule that citizenship passes through the father. Mothers were automatically naturalized into the citizenship of their Husbands, and that was the common legal practice throughout history. (Hence both parents being the same nationality.) That Congress comes along in 1934 and granted women the ability to pass citizenship on their own, makes all such citizens naturalized and statutory. It created an artificial condition which never existed before. A jus sanguinus dual citizen.
This is a very different thing from "natural." It is, in fact, about as "unnatural" as it gets. This hodgepodge of legal stupidity can actually create a "triple" citizen.
Now i'm sure Jeff is going to lyingly add Marshall to his list of other supporters which he is also mostly lying about, but this is the sort of thing we've come to expect of Jeff.