In what way is it reasonable or understandable? What on their agenda specifically targets black people? Trump took directly away money from policies that were there to support black communities. I’ve seen that first hand.
You can’t say supporting Trump is c00ning, but then say being a Republican is reasonable idea when Trump does nothing but reinforce Republican ideals and agendas, neither of which have ever been for black people. All these “don’t vote, leave the Democratic plantation” folks hated Hillary for the crime bill, but strangely had no issue with Jeff Sessions
A new party or independent? Sure, if that’s what you feel can be helpful. Being a Republican? Absolutely not.