Not forgetting the importance to a nation of a unifying principle agreed by all - the US Constitution as symbolised by the American Flag. The concept of multiculturalism defeats this unifying principle that allows assimilation and integration of immigrants and instead pits one culture aginst another in a constant battle for supremacy.
Do not underestimate DJT's overt display of love of the Flag. He knows that to unite a country there must be a common acceptance of a national principle by which a nation is identified and governed.