You mean back when Americans of all ages voted along class lines (somewhat) and working class people couldn't attend universities unless they'd had a military career before?
Of course, there were plenty of elite Democrats back then ("before the 70s" is an awfully long time), and there have always been certain working-class areas that voted heavily Republican (some since the Civil War era)....
Ah, true. It's interesting to look at the changing nature of the type of work done by the American working class. Back in the New Deal/WWII era, there were
a lot more manual laborers ("blue-collar" workers), and they exerted a major political force in the form of unions, which became one of the main components of the Democratic Party. Also, a lot more of the manual blue-collar workers back then were white....not so much anymore, for a number of reasons..
Nowadays, the percentage of manual laborers has shrunk, but what's shrunk even more is the percentage (and perhaps in raw numbers, too) of white manual laborers, relative to the population. A lot more working-class whites do "service" or even "white-collar" work of some kind nowadays (in addition to retirees and unemployed).
The deindustrialization of much of America, in no small part due to neoliberalism as well as broader technological changes, has, in my view, been a cause of the shift in American politics to the right as much as it has been an effect of it. When you have a much smaller number of unionized workers, a more heterogeneous class structure (with a few winners and many more "losers"), and the white-collar professional/management/business sector becoming even more powerful than it already was-it makes sense that the political system and process would become more reactionary (And that's not even getting into the race factor, which has always been central to America's class system...)
