That's what I figured. Personally I can kind of see it in my own family; my very old grandfather is arguably either GI or Silent, but he had FDR and Truman in office for his coming of age, so he's pretty loyal to Dems. My father, an early Gen Xer, said he was indirectly influenced to not like Reagan by his father, but I think the times he grew up in made him leaning towards Republicans by default, except for Trump. Meanwhile I'm a partisan hack for Democrats. My father's older siblings are baby boomers, but I know one of them is pretty liberal, but that might be the result of her father, growing up in liberal NY, and maybe a bit of "liberal" Eisenhower (by GOP standards) and JFK/LBJ.