Racism is a useful political tool in the United States for internal proletariats seeking empowerment for and with external proletariats. While the United States of America are just one part of America rather than all, there are several races in the states and they find social demographic composition and changes or desire to change an uneasy balance occasionally.
The United States of America may add more nations to become states in time. That is a more likely course rather than a collapse of the unification to disunion IMO. NAFTA and other trade agreements worked more toward the direction of unification than separation.
George Washington in his farewell address warned about making permanent foreign alliances quite rightly for those tend to nullify the constitution values that citizens of the states hold as vital. They are based on principles of individual rights with all men and women being equal under God. The United States can only go so far in allowing foreign entities to legally join with the United States without becoming United States for-themselves that accept the constitutional and legal values of the United States of America. Americans outside the United States with separate identities such as Canadians and Mexicans, Brazilians and Venezuelans would have to quit their seperate and dubious legal structures and accept those of the United States of America to become U.S. states.
Foreign nations and external proletariats will long seek to manipulate the United States of America along racial lines. Politicians of the states tend to be idiots equally of all races and creeds of course. There are dim prospects for selecting good political leaders able to reform capitalism and economics such that ecological economics prevail. Few even know what that is. Good ideas in political leaders should be the selection criterion rather than electing on the basis of race, color, gender or additional irrelevant for good political leadership paradigmata. In the latter case the ordinary citizens are losers and special interests; even globalist plutocratic or socialist interests, winners, to the detriment of Americans within and without the United States.