New Deal programs often left it up to the states to determine if it would benefit blacks. This resulted in the New Deal benefitting blacks in states that allowed blacks to vote while the Jim Crow states made sure to deny blacks in their states any benefits from the New Deal.
This isnt really true. Ironically, many New Deal programs were set up to further hurt blacks:
It wasnt until FDR's advisers and Eleanor pushed him to set up a
black cabinet did black voters start shifting over. If anything, Eleanor did most the heavy lifting to get blacks over to the Democratic Party:
According to Henry Fairlie, Black wards in Cleveland gave the following percentages:
1928 - Smith - 30%
1932 - FDR - 24%
1936 - FDR - 49%
So I'd say 1932, Hoover.
It's ironic that Hoover won the black vote considering he was a virulent racist himself. He opposed anti-lynching bills and was also a fervent supporter of the Lily White Policy. He intentionally did his best to drive blacks from the Republican Party by segregated them and refusing to be photographed with any black leaders. The GOP was never really the party of Civil Rights...even Taft was a racist who sought to remove blacks from the party.
Neither has ever been, hate to break it to you. Republican attitudes of the mid-Twentieth Century, for example, were the Democrats have been talking out of both sides of their mouths on civil rights for decades, so why can't we? Then, they were understandably very bitter when this was painted as any more "anti-civil rights" than the 1960s Democratic Party was.
I dont dispute that neither party cared in those days about blacks. But there is this pervasive myth among Republicans that during this time...the GOP was ''better'' for blacks. Neither party cared.