Since it is not part of the text, we have some "wise latina" trying to ascertain the meaning of the amendment, and she will not look at "original intent".
Maybe he thought that he was writing for an educated populace. At the time of the writing “... and subject to the jurisdiction thereof...” meant what you suggested. That’s why he said “of course” in his explanation... it was self-evident in the language. Then come the lawyers...
I could be mistaken, but I believe that illegal aliens are not “...subject to the jurisdiction thereof...” as that phrase is defined. If so, Senator Howard’s comments would be redundant.
Also, legislative history is relevant, though not conclusive evidence, in determining the intent of laws.
“Since it is not part of the text, we have some “wise latina” trying to ascertain the meaning of the amendment, and she will not look at “original intent”. “
That is a problem. But the 14th was written in the 1860’s. I cannot criticize Sen. Howard for not anticipating the supreme court would become the fist of radical left-wing activism. You cannot draft legislation or amendments to prevent judicial bad-faith.