Clearly 1992 was a realignment, since Democrats have won 4 out of 6 elections since then, and the way different regions have voted is largely the same since then, and it wasn't before. Here's mine:
1932 Democrats won 8 out of 12
1980 Republicans won 3 out of 3
1992 Democrats won 4 out of 6
Just for kicks to prove that '92 was a realignment, let me show you what percentages of the elections from 1932-1988 and from 1992-2012 went for a given party.
1932-1988:
Electoral Vote Count (Using Today's EVs)
Republicans- 325
Democrats- 213
1992-2012:
Democrats- 284
Republicans- 216
Tie- 38
Granted, 1932-1988 was a much longer period of time, but if that's not a realignment, then I don't know what is.
You might make it more clearly by splitting that long stretch into 1932-1960 and 1964-1988. Then you'd have 8, 7, and 6 elections in your representative maps.