That is occurring now. Where I live in suburban Chicago, we have an upcoming mayoral election. One of the candidates is Hispanic, another is black. Just about all of my black friends have adamantly told me they do not want "a Mexican mayor". Likewise, many of my Hispanic friends tell me they will not vote for a black.
Blacks and Hispanics will not share power together. It won’t work. Your mayoral race in Chicago and the US Senate race in California are gonna get nasty. Blacks have always been the nonwhite power brokers in the Democratic Party, but Hispanics don’t want to play second fiddle to them in the party power structure anymore. Sooner or later Blacks will lose a significant amount of power and influence within the Democratic Party. I don’t think they realize that yet, but the reality will be evident soon.