I have seen no evidence that he has ever asserted it, so I don't see how it is important.
It applies to dual citizenship, period. American Indians have dual citizenship by statute, but, following in your tradition, I'll leave it to you to find the relevant section of the US Code.
I also looked for your proof of citizenship and didn't find anything. Does that mean you are not a citizen? That's a rhetorical question btw.
Ask yourself this question; why would all the articles written about Netanyahu testifying before Congress in 2002, include and stress that he is/was testifing as a citizen?
Why does it matter if he testified as a citizen? Why the need to stress that or point it out? I mean Lotsa people testify before Congress and nobody reports they are testifying as citizens.
It's important to be clear and open that his testimony was comming from a citizen rather than a head of State. A head of State testifying would be violating the Logan Act and whoever violates that law could be charged with sedation or something similar. Either way, BiBis lil speech today isn't about testifying, it's just political grandstanding and Bohner will be outplayed by Obama yet again.
This is not about Obama or protocol or the GOP, this is about giving Netanyahoo a platform to pander for votes and try to raise money for his election back in Isreal. Nothing more, nothing less.