The plain language of the 15th Amendment is, of course, most reasonable. And in fact it did serve its purpose in resolving the legal status of those freed by the 13th Amendment.
But you expose yourself with your foolish remarks by failing to see abominations like Motor Voter and the endless fraudulent challenges that are undermining the electoral process (e.g. Gore 2000, Franken 2008) as being the direct result of the debasement of the Constitution that began under Reconstruction. And in this case the abuse by the Federal Courts of the 15th Amendment.