" The cause was the civil rights movement, which aroused fierce opposition among whites in the deep South, leading them to abandon their historic attachment to the Democratic Party and to vote in five states—South Carolina, Georgia, Alabama, Mississippi, and Louisiana—for a Republican Party led by a man who had opposed the Civil Rights Bill in the name of “states’ rights.†Though Johnson defeated Goldwater in a landslide, the “Solid South†was solid for the Democrats no more."
" The cause was the civil rights movement, which aroused fierce opposition among whites in the deep South, leading them to abandon their historic attachment to the Democratic Party and to vote in five states—South Carolina, Georgia, Alabama, Mississippi, and Louisiana—for a Republican Party led by a man who had opposed the Civil Rights Bill in the name of “states’ rights.†Though Johnson defeated Goldwater in a landslide, the “Solid South†was solid for the Democrats no more."
http://www.huffingtonpost.com/entry/the-roots-of-the-democratic-debacle_us_584ec983e4b04c8e2bb0a779