Islamism is the attempt to transform a traditional religion into a totalitarian, fascist-like or communist-like ideology. Today, Islamists are divided into two groups: Terrorists and politicians. Terrorists attack and politicians take power in countries that are afraid of their terrorist allies.
It is a suicidal attitude to say that the help of moderate Islamists are needed to fight the militant Islamists. Those who are called the “major Muslim-American organizations” are nothing but the political faction of Islamism. They represent a very limited sector of the Muslim-American population, but they can claim to be “major” since they have huge Saudi funds at their disposal and because U.S. politicians are unfortunately on good terms with the Saudis.
One case of this is the Council on American-Islamic Relations (CAIR)