This is pretty interesting. Are there charts that show how the votes went for the 2016 election for comparison? I would like to see how much more republican people trend as they get older.
Here is a good article on all of this, albeit outdated:
http://www.people-press.org/2011/11/03/the-generation-gap-and-the-2012-election-3/In 2016, the oldest voters (65+) trended Democratic quite a bit. They went from 56 - 44% Romney to 52 - 45% Clinton. This is probably due to the older Boomers, who grew up under Nixon, moving into the 65+ group (65 - 71). They have always been less Republican than the generation as a whole.
Here is a full chart from 2011:
As you can see, even those who grew up under FDR's administration still voted Democratic into their 70s/80s, although there might have been a little erosion over such a great length of time. That much is expected, as the parties did change a good bit over all that time, and the ones who were still alive in the 90s/2000s were those who grew up in the latter half of FDR/Truman, during WW2. Usually support erodes if a party holds the White House for a long time like that.
The biggest pro-Republican shifts among older voters came from the primary genx/boomer group: 45 - 64, which includes the older portion of generation X, and the younger Boomers, who are more Republican. The pro-R shift among 45-64 is probably due to those Boomers/genx'ers aging and thus voting more often, as well as the more Democratic older Boomers being measured in the 65+ age group.