The protests, IMO, demonstrate that some individuals don't feel they and/or others are receiving fair treatment and don't feel that same "commonality" you mention.  That, IMO, is the whole point of the protest.  

We're a long-standing democracy and that "same house" you mention needs to be large enough and strong enough to allow different views to be expressed.

  I don't see this protest as a threat to American values, but rather as a testiment  to American values.  Like the "hanging effigy" of Hillary Clinton displayed by Mr. Pitner, "taking a knee" during the Anthem is a public display of one's views.  

To me, the real threat to America comes from those (such as those who have threatened Mr. Kaepernick and his family's lives) who would silence the voice of protest...not from those who voice that protest.