From the Depression until the passage of the Civil Rights Act, Connecticut was a Republican-leaning swing state. Only a few towns leaned Democratic.
A notable change came after the Civil Rights Act, when Connecticut turned sharply to the Democrats, especially in Hartford, New Haven, Bridgeport, New London, and many working-class towns in the east. Suburban areas in Fairfield, Litchfield, and Middlesex Counties still leaned Republican through the Clinton years.
In the post-Clinton realignment, eastern Connecticut as well as the northwest corner and some affluent cities in the southwest such as Greenwich and Stamford trended more Democratic. Connecticut’s Democratic strength peaked in 2008, with the ousting of the most recent Republican congressman in the state, the long-serving Chris Shays. Afterward, the working-class towns in the east trended Republican while many towns in the west, home to New York transplants, trended Democratic.
Here are the PVIs of each city and town.
Here are the slides.
Here are the individual maps:
1928
1932
1936
1940
1944
1948
1952
1956
1960
1964
1968
1972
1976
1980
1984
1988
1992
1996
2000
2004
2008
2012
2016