Madison's statement, and the context of that debate, have nothing...not a single thing to do with "natural born Citizens."
Mr. Smith was, "No person except a natural born citizen, or a citizen of the United States, at the time of the adoption of this Constitution,"
because he was born in South Carolina prior to the Constitution (actually, prior to the revolution)...but had traveled to Great Britain and other parts of Europe. So his allegiance to the U.S. came into question...as did weather or not he meet the 7 years residency requirement for eligibility to the House of Representatives.
Madison states that William Smith's allegiance should not be questioned, simply because he was in Europe for some time....because Mr. Smith never renounced his citizenship (gained after the Declaration of Independence) and was born in South Carolina.
Their use of that quote regarding the issue of who a "natural born Citizen" is, is nothing more than an attempt at deception and obfuscation. The only question is...are they doing it intentionally, or out of ignorance?
I would say they are doing it because it is the only straw they have to grasp. :) Nothing else in the record ( of which I am aware) supports their argument.