Yeah they're college educated (first in their respective families, of course). Combine that with Good Times Boomerism and they want to gravitate towards their idea of a middle ground.
For example, my mom voted for John B. Anderson in 1980, who was definitely considered a country club Republican in his day. His platform (pro-higher ed, antitrust, pro-environment, opposition to income tax cuts, pro-gas tax hike, pro-ERA, pro-gay rights, pro-choice) would get him labeled a raging communist today, despite his typically Republican positions of energy deregulation and support for balanced budgets/entitlement spending cuts. I firmly believe she's been disillusioned with most candidates ever since.
For his part, my dad was really impressed by Mike Duggan's efforts to turn Detroit around, and is still salty that his independent campaign went nowhere.