Is there any evidence of the southern switch that had people from the Democratic party flock to the Republican party?

Short answer, yes. According to Vital Statistics on American Politics 2015-2016 (table 1-4) here’s how many Republican candidates were elected to various offices in the South, comparing the period 1932-1965 to 1966-2014. President 15.8% to 76.5%. Governor: 0 vs. 57.6%. US Rep: 7.2% vs. 45.1%. US Senator: 1.5% vs. 65%. http://bit.ly/bc-cq. You could also look at some broader studies on party affiliation like these: http://bit.ly/bc-shift