IF THE REPUBLICAN & DEMOCRAT PARTIES "SWITCHED SIDES" AS A RESULT OF DEMOCRAT'S DEVELOPING IMPROVED RACE RELATIONS & REPUBLICANS BECOMING RACISTS TOWARDS BLACKS - LIKE DEMOCRATS OFTEN CLAIM; WHY IS IT THAT BLACKS STARTED TO VOTE OVERWHELMINGLY IN FAVOR OF DEMOCRATS DURING THE 30S UNDER FDR'S NEW DEAL BENEFITS; PROGRAMS - NOT DURING THE 60S CIVIL RIGHTS LEGISLATION ERA, WHICH MORE REPUBLICANS SUPPORTED THAN DID DEMOCRATS?