I think this is way off the mark. The Reps embrace Blacks as part of the party as much as they can. They even made Michael Steele Chairman of the Republican National Committee. He was also the Republican nominee for the Maryland Senate seat. (During the campaign he was vilified by other Blacks as “oreo”, et.)
The problem is that there is a relatively tiny pool from which to draw talent. When you have 95% of Blacks voting Dem, you’re not going to have a large pool. The problem isn’t so much a lack of desire from the Rep establishment, its the success of the Dem part in brainwashing Blacks that the Reps want them held down, if not lynched.
The really odd thing is that if you look at the unemployment rate among Blacks, you would think that the party that is supposedly looking out for them would want to help them. But more liberal immigration policies just mean that lower-skilled workers (which make up a disproportionate percent of Blacks) will have a harder time of it. How the Dems have been able to pull this off is truly astonishing. Talk about opting against your own self interest! Charter schools is another important issue. You’d think the Dems would be championing them, but they’re not. The Reps are. The Mayor of NYC is getting a lot of blowback for having taking a stance that is largely anti-Charter. And that is coming predominantly from the Black community.
As far as your points about Hispanics, you make good ones. And I think you’re right that many of the values that the Rep part espouses can be found thriving in the Hispanic community. I think the problem here is again the successful efforts of the Dems to demonize the Reps as being “anti-Brown people”. The immigration debate is often framed this way. But as time goes on and we see more instances of Reps championing Hispanic candidates (and Black ones) the Dems hold on them will loosen.