politics, secret alliances, imperialism.
They didn't go far enough because although all types of institutionalized racism was forbidden by constitutional means, it didn't stop people from being racists. They still behaved like racists and often it would happen that people of color would get punished much more in court than Caucasian people, or people who were racists and did bad things against the African-American population would walk free, especially in smaller communities.
Walter Mondale lost to Ronald Reagan by a landslide.
They were there against the civil right worker's murders. While the black population at the time was allowed to vote, in the Southern states they were withheld from voting by all sorts of idiotic reasons.
Thats the answer to your answer