"From a security perspective, it is at least as plausible that the sighted assistant would manipulate the vote of the blind person as it is plausible that a hacker would manipulate the votes on an electronic system."
No it is not, because you cannot manipulate the actions of hundreds of thousands of sighted electoral assistants undetectably, instantaneously, remotely and anonymously like you potentially can with electronic systems. This is the same thing that makes postal voting a lot more secure compared to electronic voting than it might seem at first analysis. See the talk I linked elsewhere in this discussion.
No it is not, because you cannot manipulate the actions of hundreds of thousands of sighted electoral assistants undetectably, instantaneously, remotely and anonymously like you potentially can with electronic systems. This is the same thing that makes postal voting a lot more secure compared to electronic voting than it might seem at first analysis. See the talk I linked elsewhere in this discussion.