I always think it's interesting (and criminally untalked about) how poorly Reagan did in the South in 1980 compared to the dominant "realignment" narrative that has come to rule our history books.
In addition to what Mikado said, it also depends on how you view realignments. Personally, I've always looked at them through the theory of generational turnover in addition to unique elections. In this case, it might be fair to say that Reagan took advantage of a favorable electorate, and whose presidency, over the course of 6 - 8 years, shifted it further towards Republicans.
