On the 50th anniversary of the death of JFK, I think the question should be asked. Was JFK the last conservative democrat president?
If you look at Carter's de-regulation of Transportation and Communications. . .
And if you couple that with Clinton's financial de-regulation and his pro-business economic team (Richard Rubin, for instance, who loved markets and detested regulations)...
Than you see a shift to the right that continued from FDR to the present day (mostly because business became powerful enough to start buying politicians and capturing regulators)
Similarly, we saw a progressive trend that started with FDR (arguably Teddy) and continued through Eisenhower and Nixon, both of whom used Big Government to build infrastructure, regulate the economy and support many of the New Deal's positions on Labor.
These trends overlapped, which gave government a functional centrism that it lacks today. Meaning: there were liberal and conservative members on both sides of the aisle, especially if you consider Southern Democrats who are far more conservative than most northern Republicans. Carter was an evangelical whereas Reagan (and his secularist/astrologist wife Nancy) had rarely attended Church services until he needed Pat Robertson to help him gain widespread electoral support for what was essentially a business agenda. [It's funny because the Rightwing, for all their distrust of Government, completely trusted in Reagan's religious shift. At the end of the day, Republican voters have immense faith in their government leaders]
Here is how I would put it. I think the country had two distinct phases.
A Big Government (pro middle class) phase that extended from FDR to Reagan. And a pro business (**** the middle class) phase, which extended from Reagan to the present day. During each phase, members from the opposition party were forced to support the other side. For example: Eisenhower and Nixon supported Big Government infrastructure projects, the New Deal, and sensible regulations, whereas Clinton and Obama have followed the Reagan Model of allowing business to ship jobs to China, lower American wages, cut middle class programs and form monopolies over most domestic sectors (despite Obama's claim to want to restore competition to the Republican supported monopolies in health insurance).
The country is now owned by the large corporations (and their investors) who fund elections and lobby for government help. Republican voters don't understand this because FOX, as a rule, spends almost no time covering how Lobbyists apply financial pressure to politicians in order to secure subsidies, bailouts and Government intervention in the economy. I've actually tried to talk to "Talk Radio Republicans" about lobbying . . . only to realize that their news sources never talk about how much money the private sector pours into Washington and why.