I was looking at the results of the 1948 Presidential Election and a few irregularities caught my attention:
1. Why did Dewey lose ALL of the traditionally Republican Rocky Mountain and Pacific Coast States except Oregon, even with California Covernor Warren on the ticket?
2. Why did Third Party Candidate J. Strom Thurmond's vote fluctuate so widely? 87% in MS, 79% in AL, and 20% in neighboring GA? How about 72% in his home state of SC and 8% in NC???
The Mountain states have a long time populist streak that Truman would appeal to, especially against someone from New York. Many areas have a relatively significant mining industry, especially immediately after WWII. In Wyoming, the UPRR is a significant source of employment.
For Thurmond, I would guess that it was the election laws, which may have made it easy or not to get his name on the ballot; or whether one had to vote for electors or a slate of electors directly; whether there was straight ticket voting; etc. In Alabama, Thurmond was the Democrat candidate. Assuming they had the same system as they used in 1960 - electors were chosen in the Democratic primary. There might not even been Truman supporters on that ballot - or visible as such. In Mississippi, Thurmond was the Democrat candidate. Truman was the "National Democratic" candidate, a 3rd party candidate.