One reason why the GOP is more liberal in those states may have been because the party was so strongly rooted there in earlier years. You could build a Mississippi or Florida or Oklahoma GOP pretty much up from scratch in the 1960s, because Republicans had been rare in those states earlier. The Republicans were also trapped by the ethnic conflicts of the East Coast, and identified with the old oppressors.
For years in New England the Republicans had been the Protestant party and the Democrats the Catholic party, and as the composition of the population changed the Republicans lost strength. They are still a pronounced minority even though the WASP Establishment is now at least as favorable to the Democrats. What's interesting -- and alarming -- is that states where this Southern New England dynamic wasn't a major factor in past elections, like Delaware or New Jersey or New Hampshire have become more Democratic in presidential elections as the Republicans have become the evangelical party.
There's a 19th century parallel to this. The Federalists and Whigs were tied into New England's Congregational establishment. And the rest of the country wasn't interested. They might be Calvinist, but they didn't want their way of life bound up in old Puritan forms and subject to Puritan deference to authority. So the New England states were left holding on to something the rest of the country wasn't buying.
Another reason for the Democrat tilt is that older cities and industrial towns want resources from the federal government. They may not get more than other Americans, but they embrace an ideology that they think will get them what they want. Also, there's not as much cheap land for wide open development in the East, so there's less enthusiasm for economic growth.
New England's great problem was that it didn't have a large hinterland. Virginia and South Carolina were able to stamp Arkansas and Alabama with a Southern identity and to draw on their human resources to promote their interests. The Tidewater and Charleston were backwaters indeed for long decades, but they spoke for a larger region or convinced the region to speak for them. New York was able to do draw people in from all over the country to promote the idea and the interests of New York.
But New Englanders who went West didn't look back or contribute to any New England idea or way of life. Tennesseans and Texans might be as Southern as Virginians, but when Vermonters and Massachusans moved to Wisconsin or Oregon they ceased to be New Englanders in any way. And as the population and the economy changed in New England, becoming less Protestant and less rural, so did New England's politics and culture.
Consequently the region had trouble in the material and cultural competition. What it had to offer didn't "sell" on the national market, and in time, what didn't have appeal elsewhere took root in New England.
There may be more sense than we suppose in New England's choices, though. Steve Sailer wrote an interesting article contrasting the Red Republican states, where people still marry and have children, and the Blue Democrat states which are increasingly populated with the unmarried and the childness. He compares San Francisco's and Los Angeles's responses to growth in recent years. Northern California embraced a low growth Democrat point of view. Los Angeles went in for high growth and rapid development. Both cities have changed a lot in recent decades, but Sailer's idea is that change got more out of control in Los Angeles.
That doesn't mean that San Francisco made the right choice in going left, but Republicans in LA and elsewhere have sometimes overestimated the degree to which they can combine rapid change and conservative politics. Northern California or Vermont choose greater political control over greater economic freedom, but they may simply have chosen a more direct path to where other parts of the country will end up in the future.
Actually the Yankee diaspora still has echoes. Bush ran relatively poorly in most places where Yankees are a significant force. Of course, now it is a reflection of values. Yankees tend to be secular. Kevin Phillips picked this up in his seminal book, The Emerging Republican Majority. On this matter, his thesis continues to have traction.
Your analysis is impeccable, as usual. Thanks.
I don't think NH is becoming like DE or NJ.
There are lots-LOTS-of very, very conservative people here-one of the reasons it's so good to live here.
But W has not ever been really popular here-McCain destroyed him in 2000, and although this year was close, he didn't light any fires.
I think it's cultural-the "some people say I swagger, down in Texas we call it walking" just isn't a vote multiplier here the way it is in dark Red America.
This year past, Effin' had hordes of GOTV from over the line, and the top of our State ticket was a sleaze who repelled voters if anything.
We'll be red again next time. Bet on it.
The same was true in Pennsylvania, Ohio, and Minnesota. However, the driving force behind the GOP in those states were German Lutherans, Mennonites, and Anabaptists.
You also forget the strength the GOP had in Italian areas of Rhode Island, Massachusetts, upstate New York, and even Illinois and northern Ohio from the 1920s-1980s.