What’s your basis for making this claim? Polling? With regard to Chicano voters and immigration, it might be true that when asked to list their policy priorities, immigration reform might not be on top, but there’s another way to interpret that.

Immigration is likely to be on top of white conservatives’ agenda because they’re primed to view it in alarming terms as a “crisis” or an “invasion.” Chicanos on the other hand don’t view it that way but they’re still nonetheless concerned with related issues, and in particular the demonization of brown people by the Trump administration, the internment of children, etc.

As for criminal justice reform, strictly speaking, it’s not the “top” priority for black voters, but it’s still high up there.

The top priority is racism and discrimination, which cuts against your thesis that “identity politics” don’t matter so much to black voters. They clearly do, and this, again points to an area where Biden is vulnerable due to blotches on his record with respect to black civil rights (opposing busing, being chummy with Strom Thurmond).