The 1970s was right after the democrats got together with the republicans and decided to swap party affiliations.
Following the civil right act, democrats called themselves republicans, except for Robert Byrd who never renounced the KKK until 1982.
there was no such "swap"
that is a carefully crafted meme designed to conceal the democrat's sea change on race (in public)
after the 64 civil rights act and the voting rights act, many black leaders in the south hatched a plan, instead of joining the republican party (the party of abolitionism and civil rights), the black leaders encouraged their folowers to register as DEMOCRATS and overwhelm the racist democrat party with their numbers and thus change the party from within.
while the republicans had welcomed black voters, and even had black delegations back in 1870 as well as the first black congressmen in that same year. (previously blacks had not been considered citizens)
in 1968, when the democrats, led by the Daley Machine kicked the first ever democrat black delegates out of their convention in chicago, and the brutality that followed, the democrats went into a tailspin.
faced with their party becoming a joke, the democrat leadership bowed to the inevitable and stopped fighting against civil rights.
over the next decade democrat leadership created a new fictional history for their party, claiming leadership on civil rights, and extolling their glorious resistance to racism (for black and liberal audiences) while maintaining their strangle hold on southern politics by only making their real views known from behind the anonymous security of a white sheet.
careful examination of what they DID rather than what they said makes clear that the democrats of the 70's were still liberal in the north, and racist as fuck in the south
in the 70's nixon's idiotic "southern strategy" to woo racists from the democrats was based largely in the butthurt over republicans feeling slighted when newly enfranchised blacks swarmed into the democrat party (to seize control of that party, not because they were grateful, only idiots could believe that) leaving the republicans to remain a minority in the south.
the endlessly repeated meme of a grand party switch, where democrats suddenly eschewed racism, and republicans perplexingly scrambled to adopt it's every tenet is RETARDED.
nor did all the racists flee the dems to become republicans, nor did all the non-racists abandon the republican party and become democrats. if that were the case, Robert "Grand Cyclops" Byrd would not have retained his senate seat (as a lifelong democrat) until his death in 2010.
while it is true that DEMOCRATS abandon their party for political expediency (see Bloomberg) quite frequently, when a republican switches, IT'S NEWS.
conservatives believe in loyalty and choose their party for the platform it espouses and the ideas it supports. these ideas (like robert byrd's love for the Klan) dont change overnightand republicans rarely switch party, but when they do, it is to choose independant, libertarian, or some other third party, the do NOT become democrats. that would require abandoning everything they believe in, and if they can do that, they were never conservatives in the first place.
TLDR version: there was no "great switch", thats a bullshit meme to make democrats feel better about their historical (and continuing) opposition to civil rights
