I don’t think it would rise to the level of treason unless such subtufuge was shown to be a conspiracy between Obama and a foreign power. While Obama may not have been a natural born citizen, or even surrendered his citizenship when he moved to Indonesia, it would need to be established that he is now a legal citizen (and not just someone who returned her and reclaimed surrendered citizenship) who sought to provide aid to a foreign power (enemy). You have to be a citizen to be a traitor, I think.
Now those in Hawaii, Illinois, and DC who may have engaged in a criminal conspiracy to empower a foreigner as President WOULD be considered to be in league with a foreign power/enemy to circumvent our Constitution.
In the Cold War, stateside Communists engaged in espionage and subsidized seditious movements against the government ON BEHALF of the Soviet Union.
Barack COULD be considered a traitor for restoking the Cold War (we were not at war with Russia but he wanted to take up “peace negotiations” and sought the destruction of our own nuclear capabilities even if the Russians are not compliant as well as disclosing our missile locations to foreign inspectors).