“I do not agree with his opinion, nor with his other supporters who agree with him 100%, that Article 2 Section 1 Clause 5 is no longer relevant.”
Do you consider Senator Santorum to be a natural born citizen?
Well, what are the particulars regarding citizenship with Mr. Santorum? He's never been in a position for natural born citizenship or the lack of it to have any bearing. Sure, he ran in the Republican primary, but apparently most any schlub with financial backing can do that these days.
Was he born in the United States, or elsewhere? If elsewhere, did any foreign sovereignty make a legal claim of jurisdiction over him due to having been born there?
What other routes are there, for a foreign sovereignty to make a legal claim of jurisdiction over Mr. Santorum? Were there any claims via descent, meaning through either of his parents? If so, was any such claim absolute, meaning Mr. Santorum was subject to the jurisdiction of a foreign sovereignty due circumstance of parentage?
Or, perhaps there was a generational offer of citizenship, with the jurisdiction that comes along with it, that required some sort of affirmative act? If so, was was such an offer ever affirmatively acted upon?
You see, it's really not so simple, as the State Department has confirmed for quite some time, likely as long as it has existed. It's not a matter of subjective opinion and it's not a matter that is resolved by emoting.
If some other legal system has it's hooks in him, he should not sit as President and in fact was precluded from doing so. If no other does, then he can.