Bear in mind, this is not the opinion of some nobody like myself. The following is the opinion of the United Nation's lead investigator into torture. Therefore, the following can be taken as the comments of an expert.
“Like all other contracting states to the UN convention against torture, the US has committed to conduct criminal investigations of torture and to bring all persons to court against whom there is sound evidence,” Manfred Nowak, the UN’s Special Rapporteur on torture, told Austrian weekly paper Der Standard.
“They are party to the convention and the convention is very, very clear,” Nowak told the paper. “The fact that you carried out an order doesn’t relieve you of your responsibility.”
“In a brief telephone interview with The Associated Press, Manfred Nowak [...] said the United States had committed itself under the U.N. Convention against Torture to make torture a crime and to prosecute those suspected of engaging in it,” reported the San Francisco Chronicle.
So, we now have an expert in a field stating openly that Barrack Obama is in violation of international law. That does not mean he's guilty. But it does mean that in a society that respected laws and the constitution that impeachment hearings into this case should be begun. When you have an international expert stating that the leader of your country is in violation of international law, a lawful society would take steps to correct the problem.