For example, which state has the highest African-American percentage in its legislature? Mississippi. If we were so racist, we would have not have allowed that through gerrymandering and intimidation.
Are there any white-majority districts with a black senator/representative or any black-majority districts with a white senator/representative?
Ok, for what it's worth, there are a few.
MN-05 (73.5% white) - Keith Ellison (Minneapolis)
MO-05 (68.8% white) - Emanuel Cleaver (Kansas City)
IN-07 (63.0% white) - Andre Carson (Indianapolis)
WI-04 (54.8% white) - Gwen Moore (Milwaukee)
GA-02 (51.4% white) - Sanford Bishop
CA-09, GA-13, NC-12 are plurality white but have black representatives.
CA-33, CA-35, CA-37, NY-15 are pluarity hispanic but have black representatives.
FL-03, MO-01, TX-09, TX-18, TX-30 are only plurality black but have black represenatives.
Also, though it doesn't really count, IL currently has Roland Burris. However, they did elect Obama in 2004.
Correct me if I'm wrong, Boris, but I thought you were referring to such districts/representatives/senators IN MISSISSIPPI where that is the case. If we're comparing racism in different states, having blacks representing black-majority districts would not attest to non-racism.