Racial Voting Blocs

After consistently seeing black Americans consistently vote 90%+ for Democrats in presidential elections, isn’t it obvious that black Americans are an almost official racial voting bloc of the Democratic party?

What will the Republicans do strategy wise about this, seeing as though even giving blacks like Condi Rice, Colin Powell and Clarence Thomas to name a few prestigious and powerful positions, that black Republicans seem to be as rare as a spotted owl flying through Harlem.