This essay doesn't say what happened between the mid 1960s, when Republicans passed the civil and voting rights acts over the objections of the Democrats, and now.
What happened that shifted the black vote away from the Republican party? Did the black community leave the Republicans, or did the Republicans leave the black community?
A prominent Republican, Sen. Barry Goldwater, the party's presidential candidate in 1964, refused to vote for the Voting Rights Act.
His reasoning was clear. The Act applied in only 13 of the 50 states. Only the states of the old Confederacy were subject to the law. Therefore, it was clearly unconstitutional -- an affront to "equal protection under the law".
The Democrat Senate leadership and the Johnson administration refused his demand that the act be made to apply to all fifty states.
Goldwater, a principaled man -- and the furthest thing from a racist -- paid the price for his principals. And the GOP paid along with him.
Until 1936 republicans always won the black vote. In 1932 Roosevelt got 23% of the black vote, in 1936 the switch was made, and it was permanent, in 1936 Roosevelt got 71% of the black vote while the GOP got the 28%, a complete and instant, and permanent reversal.
The democrat presidential candidates never had to sweat the black vote again.