Obama insists that ISIS is "Not Islamic" despite the fact that ISIS's flag matches the original of Prophet Mohammed. Obama insist that ISIS is "Not Islamic" despite the fact that ISIS imposes the Jadzia tax on Christians and uses rape and torture not only into intimidate, but also initiate captured men to become their Jannisaries.
More importantly, ISIS not not represent true Islam according to the propagandists, but Tea Partiers are still Domestic Extremists according to those same propagandists. ISIS does not represent Islam, yet is called radical islam, and is so evil that the anti-war left are becoming hawks and they are being joined by their establishment Republican buddies.
The citizens are rallied against an external enemy (they can be made up, but historically, the more genuine, the better a government can rally its people) and anyone who questions official government policy is unpatriotic. As time goes on, dissenters are increasingly scruitinized, then classified, then targeted. Adolf Hitler and the Nazis did this to the Jews, using the threat of Communism to unite the country and turn Germans against the Jews (while simultaneously sharing Poland with those same Communists).
Similarly to the Nazis being frenemies with the Soviets, the US is arming ISIS. Arming them and using them against a third party.