It is not unusual for people at that age to have dementia, so arguing with them is pointless. While people may have racists thoughts, they generally keep them to themselves, but when their mind is gone that civility check dissappears.
It reminds me of an incident many years ago on the bus where this clearly deranged elderly woman began harrassing a young philipino woman, and eventually started chasing her around on the bus until other passengers put themselves in the way to protect the young woman. This old woman was screaming racist stuff about immigrants, going back to your own country and shit like that, and for no reason at all, the girl was just sitting there minding her own business. The bus driver stopped and kicked the old bag off, but ya, she pretty clearly had some mental issues.