Someone answered my question well, but in a different thread.
As is not my usual practice, I am showing a map without a legend. I would like people to think of the significance of the color design.
Hints:
1. White stands for an even split in something, if not everything.
2. This map involves four Presidential elections in which two Presidents were the winners.
3. As is conventional in this Forum, red stands for Democrats and blue for Republicans.
4. In the last two Presidential races in which someone won electoral votes as an independent candidate running on a segregationist platform, Leip uses the color green (which is not a reference to Robert LaFollette winning Wisconsin in 1924).
5. Figure why I have no deep red but plenty of deep blue.
I have an educational purpose for such an eccentric practice. I want to see some responses before I give the key.
OK. The two pairs of elections involved are 1952/1956 and 2008/2012. American politics have changed much in sixty years, but largely because people who fit demographics that used to vote reliably Democratic (except for racist dissidents with the national Democratic Party when it went 'too sympathetic to black people' for their tastes) and some who fit the demographics of Republican voters in the 1950s have switched sides. In the 1950s the Republican Party was not racist. This was long before any Southern Strategy that lured white people who harbored fears of black people wielding political power.
Eisenhower did nothing to show support for segregation. He never promised to re-segregate the Armed Forces. He concurred with the Supreme Court on school desegregation. At that he was as 'objectionable' as Harry Truman to white racists. Stevenson successfully brought the Strom Thurmond voters of 1948 back to the Democratic Party, but that was far from enough to win the Presidency either in 1952 or 1956.
I can now discuss the color scheme. Gray indicates Alaska, Hawaii, and the District of Columbia, none of which voted in the 1952 or 1956 elections. I am not going to speculate on how those states or DC would have voted in 1952 or 1956. Those states and DC account for 10 electoral votes.
Deep blue indicates that the Republican nominee won the state in all four of the relevant elections to this map -- '52, '56, '08, and '12. Except for Tennessee, which unlike its neighbors voted twice for Eisenhower, those states line up along the US 83 and US 89 corridors. Eastern Tennessee was long an R-friendly area, which may have made a huge difference. Those states, less NE-02, account for 99 electoral votes in 2012.
There's no deep red because no state went for the Democrat in all four elections. Only one state, North Carolina, went Democratic in three of the four elections. In pale blue are Indiana and NE-02, which went Republican in three of the four elections. Those categories account for 27 electoral votes in 2016.
States in deep green went Democratic in two of the four elections but for Stevenson and not for Obama. Those in pale green split in the elections of the 1950s but went for Republican nominees in 2008 and 2012. They account for 77 electoral votes as of 2016.
The rest in white split evenly between Republicans and Democrats -- but Eisenhower and Obama won all of those states twice! They contain 325 electoral votes as of 2016. Eisenhower is the only Republican to win Massachusetts and Minnesota together since the 1920s, and he did that twice. Tellingly, Massachusetts was the only state to go for McGovern in 1972 and Minnesota was the only state to go for Mondale in 1984 -- and those states were the best two states for the Democratic nominee in those 49-state landslides.
