"The question is whether you would take that platform as a reference to determine what a republic , and the political philosophy of republicanism that advocates it is."
No. I think it a given that a republic is a collection of states joined as a nation into a union of states with certain rights of self governance.
So you won't use the Republican Party platform as the measure of what republicanism is, but you will use the Libertarian Party platform as the measure of what libertarianism is?