A tale of two demographic "bases"

[Heimdal]

I think the explanation might be that there are a lot of people in Connecticut (specially CT-05 and 04) that define themselves as Republicans, even though they may have voted for Obama for president, and maybe even Blumenthal in the Senate election last year.
The same think might not be true for Mississipi, which used to be a One-Party state at the local level until a few years back.