silent majority

Definition

Media Studies

  • noun the idea that there is a large section of society who agree with a particular point of view, but that they have not yet spoken up to confirm this

Idiom of “silent majority”

the mass of people, who don’t have strong views, and who are not heard speaking in public as often as those who do have strong views
http://www.dictionarycentral.com/definition/silent-majority.html