Actually, this was pretty simple:
1) President Barack Obama's mother is a citizen of the USA, and was at the time of his birth.
2) ANY child of a citizen (male OR female) of the USA is, itself, a "narural born" citizen of the USA until the age of 18, when that child MAY opt for 'other' citizenship.
3) Barack Obama made no application on or after his 18th birthday for citizenship other than that with which he was born.
4) QED - Barack Obama was born/is now/remains a natural born citizen of the USA!
5) QED (again) - Arizona House of Representatives is a pack of fools.
See? Told you it was simple.
Oh, and that Item 2 thing? Think of all the GIs since WWI who spent time in foreign lands. Now, think DNA testing. And you thought ILLEGAL IMMIGRATION was a population expansion problem? Heh-heh-heh...