Perhaps it is more pertinent to ask whether THIS situation (Near but not Total dominance at the national level) can be replicated for the GOP in the South. What does everyone think?
I think it's the direction everything is moving in the south. If you are ambitious for higher up offices most white southerners will see that the GOP party label is "an advantage" (as you've pointed out) and the Democrat label is a "Disadvantage". Eventually a % of the African American voters will get tired to losing and migrate to the Republican party too, but that will take another 20 years.