Firstly:
Low-income groups tend to vote Democrat, and Blacks have high poverty rates, high unemployment rates, low educational achievement, and low median income. For these disadvantaged groups, the Republicans' "rugged individualism" has less appeal than the Democrats' "we're all in this together" message does.
Secondly:
75% of African-Americans are born out-of-wedlock, and a significant amount grow up under a single-mother. Whereas Democrats will extol the bravery of single-mothers, Republicans will frequently praise the traditional, two-parent household and publicize the well-documented effects of single-motherhood (i.e. more crime). Indeed, Black women vote Democrat by a significantly larger margin than Black men do.
Thirdly:
Republicans are less favorable towards affirmative action, criminal justice reform, the war on drugs, and public schools than the Democrats are; and Blacks care about those topics.
Fourthly:
There is a popular conception that many Republicans are racist, as provoked by the Republicans' support for law-enforcement ("Blue Lives Matter" over "Black Lives Matter") and their opposition to illegal immigration.
-I think Republicans are coming around with Mike Lee and Rand Paul working with Cory Booker on that topic.
Illegal Immigration-I don't think anybody is in favor of illegal immigration. Its just too hard to deport 12 million people that are here illegally though.
75% of Black Children are born out of wedlock-I think that is tied to income. I mean a single mother trying to take care of a kid by herself is hard with only one person bringing a check home. About Black Men voting more Republican than Black Women White Men vote more R than White Women and Hispanic Men vote more R than Hispanic Women.
