The Civil Rights Act of 1964 had been introduced by the Republicans in the 1950s, but had been decisively voted down by the Democrats. Same thing for anti-lynching legislation. So why did LBJ change his mind in 1964 and get enough Democrats to go along with the Republicans to get it passed? LBJ explained in his own comments:
These Negroes, they’re getting pretty uppity these days and that’s a problem for us since they’ve got something now they never had before, the political pull to back up their uppityness. Now we’ve got to do something about this, we’ve got to give them a little something, just enough to quiet them down, not enough to make a difference. For if we don’t move at all, then their allies will line up against us and there’ll be no way of stopping them, we’ll lose the filibuster and there’ll be no way of putting a brake on all sorts of wild legislation. It’ll be Reconstruction all over again.So it should be no surprise that with all the "help" provided by the Democrats, blacks and the poor are worse off than ever. A commenter on this notes "Given the ultra-racist history of the Democrat party, it is simply impossible for me to believe that no one in the party understood this would happen. This was done on purpose and by design. Black Americans were solidly Republican before LBJ's administration." And I would note that included that famous Republican, the Rev. Dr. Martin Luther King.