1) Although it is understandable that President Obama would show his long form birth certificate, the act will not quiet the birthers (to be fair the Democrats had their own crazies in the form of the 9/11 truthers, although I don't recall John Kerry attempting to use that as a legitimate platform in his campaign). The reason being is that they are not interested in anything remotely resembling the truth or actually finding it, but only in having their own prejudices and delusional suspicions confirmed. So fuck them.
2) Donald Trump probably doesn't give two shits whether or not the president was actually born in the United States. He only cares about what will serve him best in his supposed presidential run, and latching on to the birther theory was the best way to both align himself with the Republicans' racist, basket case power base and get the necessary media attention he craves like fiends need freebase. His blatant disrespect of the president by hammering him on a long-disproven fringe theory (and is now attempting to cast doubt over his educational background) is only matched by his ass-backwards arrogance in claiming "I have done a great service to the American people." So fuck him.
3) I try not to make generalizations, but anyone who still clings to the belief that President Obama is not an American citizen that is not certifiably insane is a fucking moron. And oh yeah, fuck you.