that is because what those folks feared happening is now happening
my grandfather and father were far right GOP in the south way way before it was cool although both refused to join the Citizens Council and were moderate on civil rights but before they each died they expressed fear that what folks they view as white extremists feared was now going to happen along with the path to Socialism and Godless culture
it's sure not hard to see their fears and those of the racists of the time were not unreasonable looking back now
but even they could not see the immigration issue and how basically every minority in the country would align with liberal mostly urban whites to form this hard majority and force this on the nation
that is pretty much where we are now...the canard that as minorities became more prosperous they would get more conservative is just that..a myth
The key is that so many have decided that their prosperity is dependent upon the Democrats. Middle-class blacks are thinking that if Affirmative Action went away, they would lose their middle-class jobs, and their kids would not be accepted by good colleges. Plus many work in the public sector.