Your history is open to question, as it accepts the Democratic Narrative that posits the Republicans want to Bring Back Slavery. Barry Goldwater was the standard-bearer in 1964. He received only five percent of the black vote. His stand on the Civil Rights Bill was the reason he got so little from black America that year. Consider that in 1960, Richard Nixon, Richard Milhous Nixon received somewhere in the neighborhood of forty percent of the black vote.
If any Republican in this era received forty percent of the black vote, there is no way a Democrat could be elected.
Nixon's "Southern Strategy" was not based on an appeal to racism. Even in the Spring of '68, before such a strategy began to take hold, it was clear that black voters were going all out for Bobby Kennedy. Nixon and the Republicans correctly wrote off black voters that year.
The Southern Strategy was based on an appeal to southern voters who were dissatisfied with the conduct of the Vietnam War. The Democratic Party was the author of the stalemate in that war, and Nixon offered to "cut bait", which suited Southern sensibilities just fine. Democrats do not like to recall their incompetence during those years; their tomfoolery grated on the sensibilities of the South. Given the fact that a whole lot of Southerners had volunteered for combat duty during that war (we Johnnies are like that, you know), this should come as no surprise. The sheer stupidity of the Democratic administration of the day led to the revolt by Wallace. It is hard for me to see how Wallace could have developed an insurgency against Johnson/Humphrey were it not for Southern anger over the fact that we weren't winning the war.
By 1970, the Republican Party recognized that black voters were irretrievably lost to the Democrats for some time to come. You are correct in this regard: Johnson's reputation from the Civil Right's struggle and the "War on Poverty" (which, in Reagan's famous phrase, was won by Poverty) helped cement the bond between black voters and the Donkey Party. There was very little that could be done to remedy this.
I have been in and out of Republican campaigns for 25 years. I haven't seen the disdain for black folks that you describe. Probably because it doesn't exist. The Klan, you will recall, was an organization made up primarily of Southern Yellow Dog Democrats. Yes, we lay down with a few dogs (David Duke latched his ass onto our party for a while) and got up with some fleas, but that happens to everyone in politics.
We Republicans are practical, pragmatic people. If no one wants to play in our sandlot because they think we burn crosses there, even if you insist that no crosses have ever been burned in your sandlot, then why waste your time asking them to come and play? Why not go after Hispanics, Asians, and Indian immigrants? Why go address the NAACP Convention if all they're going to do is accuse you of murdering James Byrd again?
We have better, and higher, things to do than appeal to people based on their skin color. Eventually, conservative arguments will carry the day. They usually do. Conservatism as an ideology doesn't posit nonsense about Man as a Fallen Angel who only needs the next marginal dollar from the taxpayer to bring the Millenium to pass.
Conservatism works because Conservatism makes sense. No matter what color you are.
Be Seeing You,
Chris