According to a poster, MGB, here: http://www.therightsideoflife.com/2010/02/22/eligibility-hi-petition-launched-in-spite-of-introduced-bills/ they state that the 1910 and 1930 Census, as well as Agnew's father's WWI registration card state the he was a Naturalized citizen. His WWI reg card is dated Sept. 12, 1918 and Agnew was born Nov. 9, 1918. Coupled with a 1910 census listing that status, it appears that his father was Naturalized prior to the birth of Agnew. Therefore, Agnew would be NBC.
Of note, apparently the 1920 census lists his father's status as alien. However, that same census also lists the wrong year of his immigration.
That about ends the speculation of Spiro Agnew’s NBC status. I would think that all the presidents and all the VPs have been sifted through and scrutinized about their origins by both the right and the left since the Obama.
Even though, in the only verified case of someone with that status becoming (de facto) President, that status was not known to the public when he was elected (VP) and/or became (de facto) President.
Really, really desperate.
As if "public opinion in the late 1880s or the late 1960s/early 1970s has anything directly do with the original meaning of any term in the Constitution in the first place. It means what it meant when written and ratified. Nothing more, nothing less. That's the way written contracts and Constitutions are.