[OneWingedShark]

If Obama should resign, all his activities and "accomplishments" will remain in effect! If he is impeached and convicted, all his Executive Orders, signatures on passed laws, become NULL and VOID

That's not how it works.
In order for that to happen, you would have to find a reason why he was Constitutionally ineligible to hold the presidency — IOW, the only way for this to be possible is the Natural Born Citizen clause. (And even then it's a crapshoot; the legal people might try pulling something out of their asses.)

[Lurking Libertarian]

And even then it's a crapshoot; the legal people might try pulling something out of their asses.

Google "de facto officer doctrine."

[Arthur McGowan]

I think at that point, Obama’s lawyers would be willing to admit that Soetoro is the child of Frank Marshall Davis, making him an American citizen, possibly an NBC.