The vast majority of American Muslims would report extremist activity within their community if it were brought to their attention. Donald Trump is wrong to say that Muslims in America are not supportive of fighting extremism. Furthermore, he may be alienating many with is harsh comments. In short, Donald Trump is off base with his comments about Muslims in America.
Donald Trump is attempting to paint a wide swath of Americans with a broad brush. He is making people afraid of their neighbors. The evidence says that Muslim Americans do report other Muslims when they fear that those people are becoming extremists. There is no reason to vilify all Muslims.
American Muslims are people just like anyone else. They are peaceful people who would not intentionally cover up terror plans any more than any other group of people. There are always people that are afraid to rat out another of their group, but this is not limited to Muslims. There are also many more people that believe in doing the right thing and would not turn their back on a problem like this, and Muslims make up just as much a part of this group as any others.
Muslim-American, Muslim - German, Muslim India and so on and so forth ! And they want to be Muslim first and last and only their country they belong to comes in the last! And do they sing and respect the national anthem of respective country they say? No is the flat answer.