Since Trump said the same thing about Chris Wallace I’d have to say Erickson is either willfully blind or isn’t literate enough to entertain the possibility of this being a case of mixed metaphor, “murder in the eyes” and “out for blood” combined into sort of a metaphorical portmanteau.
To be sure it is not incorrect to say the opening of the Fox debate might lead one to believe Meggy was both “out for blood” of the Trump variety as well as had “murder in her eyes”.