That term actually goes back to the 1980's when Reagan Republicans were desperately trying to siphon off some of the solid Democratic support from the African American community.
They came up with this bizarre and Orwellian phrase with the hope they could confuse and deceive enough black voters to switch sides, and come over to the party of private jets, polo playing, yachts, summer mansions, and "private everything" from gated communities, to schools to sometimes even churches; in other words, places where black people only appeared as servants and low level workers.
Yes, "leave the Democratic Plantation" and come over to the party of Spiro Agnew, Strom Thurmond, Richard Nixon's "Southern Strategy", Lee Atwater and his "Willie Horton" commercials, lawn jockeys, racist "jokes", Ronald Reagan with his "welfare queens driving Cadillacs" and opening his 1980 campaign just a stone's throw from the murder site of 3 civil rights workers, Rush Limbaugh and his mocking, vicious tone whenever he quotes a black man, voter "caging" and intimidation of black voters in Florida, intentional "Voter ID" laws to suppress black turnout, phony and fraudulent charges to defund overwhelmingly black ACORN, "funny" greeting cards from GOP party officials with racist stereotypes of Obama, doctored, edited videos from O'Keefe and his benefactor Brietbart, and condescending, patronizing, creepy protestations from rich white guys who insist they "have nothing against conservative blacks (a.k.a. "the good ones") and on and on and on and on and on...
What's amazing isn't the fact that black voters overwhelmingly support the Democratic Party, despite their imperfections and shortcomings; it's the fact that Republicans manage to get more than .0001 % of the black vote in ANY election.
Unless, of course, you're willing to smile, "behave", and parrot all of the nice, predictable, required cliches about bad taxes, bad government and how much better we'd all be if we were just "free" to make millions---or to go starve in a ditch somewhere...
Republicans continue to think black voters are stupid. They continue to put these shameless hacks, quislings and shills out there, and assume that they'll get African Americans to robotically follow any loud, pompous man as long as he has dark skin. Duh. Most people, white or black, are a bit more conscious.