Right, relying on the personal intent of the author is not exactly what most of us are advocating. Rather than the subjective intent of the author, we should be looking at the meaning of the words or phrase as was understood at the time that the language was voted on. To do this, you need to look at how the relevant words and phrases were understood at the time. A lot of the same phrases and words were used in various contexts during particular eras. It can be useful to know what the author thought the words meant not because of his personal, subjective intent but because if the author expressed a view, it might reflect what everyone else understood as well. Or not, which is why people study these things. (Isn’t it something like the Bible? The meaning of some parts is obvious to almost anyone yet we can still benefit from an explanation of many other parts.)
The 14th was probably the most contested amendment in history.
Why do you think Jacob Howard's quote on intent is the only one you read in these internet discussions, and why do we assume that his spin was the way the "phrase was interpreted at the time"?
What about all of the other Congressmen as well as all of the representatives in the states who argued for and against the amendment?
I don't pretend to have read the Congressional Record or the transcripts of all of the debates in the states, but I do know for sure that one Senator's ambiguous statement means very little in the context of a constitutional amendment.