Interesting the electoral map of the 1956 election shows all the states the Illinois liberal Stevenson won were in the south which at the time was controlled by conservative Democrats trying to hold onto a segregated society. Stevenson couldn’t even win his home state.
Southern Democrats, obeying their Republican hating grandparents with Civil War aftermath memories, actually facilitated the today’s dominance of the Democrat party by the liberal northeast and west coast urban areas. In another decade the Democrats would capture the southern black vote, and destroy segregation, under a southern democrat president, Lyndon Johnson. The southern whites, who voted for Stevenson in 1952 and 1956, would switch to the GOP in 1969.
Today the GOP hold on the south is threatened by the influx of northeastern liberals moving into the southern states combined with the solid black democrat vote and the influx of immigrants across the southern border. For a conservative party to hold the south (or capture other states) it must convert a large segment of the Hispanic vote (2nd and 3rd generation immigrants) or the black vote. This is what drives the “moderate” policies of the Bush family, Paul Ryan, Mitch McConnell, Karl Rove and other establishment leaders.
It looks like Southerners had started to figure out the situation in 1964, by the looks of the electoral map