My Father (since deceased) was fairly conservative nearly all his life. Until he started collecting Social Security. Then he became a one issue voter. He would vote against anyone he thought would tinker with SS (which was almost always Republicans).
The SS system was designed by the #6 crowd to fracture the family and society. It has worked in some cases like your father, but mostly the aged are too bought into Walter Cronkite to know or bother to learn the facts. Nonetheless voters 65 and older backed Trump 53-45. Not as good as Romney did, but good considering it was Trump.