As Hispanics assimilate (just like the Irish, Italians, and Jews did), they will become part of the white mainstream (at least the majority of Hispanics who have white skin), so America will never truly be majority-minority (or anywhere close to it).
Yeah but most of those groups assimilated during Plessy v. Ferguson which define race by white and black. Those days are long over. If your talking about Cubans and Puerto Ricans assimilating then your right but they were always white there is not much difference between them and peninsular hispanics. What the op meant was Mestizos who are genetically similar to what we call Native Americans. I doubt they will assimilate because 1 Mexico is right there and 2 most want to retain their Mexican/Mesoamerican identity. They will likely if not already go the way of African Americans were they do not assimilate with American culture but American culture assimilate with them. For example American culture has taken so much from African Americans in fashion, music, cuisine, and vernacular especially for a minority group. So much that they complain about cultural appropriation. That is the future of Hispanics Americans. If your are saying that Hispanics climbing up the economical ladder is somehow equivalent to the assimilation of white people that is not only idiotic but insulting.