Have you guys even bothered to read my wikipedia link?:
If there is anybody the Republicans should blame for costing them the black vote it's themselves. Sure, FDR supporting welfare might've put them over to the Democrats permanently, but it was Hoover's hardon for the vote of White Southern Protestant businessmen (thus why he also campaigned on Prohibition and anti-catholicism. Because black rights don't mean a damn as long as he kept those catholic micks out of office (yes believe or not the immortal "pro-civil rights" Republican party was full of bigots back then, whether you like it or not).
Indeed. So that must be why FDR was the first Democrat to carry the black vote.