FR discussions on this topic have a tendency to disappear down bewildering rabbit holes rather quickly. For a high-level introduction to the various claims and counter-claims and the disputes about the facts and the constitutional law, I recommend starting with the Wikipedia:
http://en.wikipedia.org/wiki/Barack_Obama_citizenship_conspiracy_theories
Read these two documents. That's all you need to get up to speed quickly.
You supplied this link...
http://en.wikipedia.org/wiki/Barack_Obama_citizenship_conspiracy_theories
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Yep, just what conservatives need... having “Obama Derangement Syndrome” identified and documented for posterity’s sake, so they know what happened to a very small segment of the conservative movement, when they went clinically insane at the election of Obama.
I mean..., I sure didn’t like it either — but fortunately I didn’t go “certifiable”... :-)