How would the 15th amendment change southern politics?

The 15th Amendment gave African American men the right to vote which would mean  they can vote in  general  elections and possibly completely change the outcome of an election

Explanation: The 15th amendment was  ratified during reconstruction after the civil  war and still with racism rolling  through the south African  Americans could now vote how they  wanted, but throughout reconstruction southern states would try numerous times to limit the black vote through poll taxes and other things.  

History is not an exact science. The facts remain the same for all historians to people but their viewpoints always differ by definition, leading to different interpretations.

So, coming into an agreement on historical research is really, really hard, but then again - human society is built on a variety of opinions.