Duo citizenship is also unconstitutional. It suggests a split allegiance. It's clear in the intent.
The constitution we have to deal with is not the same constitution you are talking about when you mention original intent. The constitution for good or ill has been modified by activist judges. There is plenty of supreme court case law that supports dual citizenship. Whether or not a person born a dual citizen is a “natural citizen” as far as qualifications for the office of the presidency is up for grabs, but it is not a clear cut issue.
I’ll lay odds that this challenge isn’t resolved before the O is inaugurated.