Ah, OK. So this drop in the top line reflects the die-out of the WW2 generation. The oldest boomers are only 71, after all, and if you’ve already lived to 71, the stats say you’re going to live on average into your late 80’s.
I’d have to give this chart some thought; I am not sure it really says what Pew says it says. Or how meaningful it is. In some respects, it’s more like a “Well, DUHHHHH” — — obviously you didn’t have any millenials voting in the 80’s and 90’s, because they were busy playing with video games and Barbies.
The data I referred to shows that the % of voters who are senior citizens will continue to rise until the mid 2040’s, at which time the early Boomers will start to go on to their Great Reward at a faster rate than the smaller GenXers will be retiring. So, if you draw THAT graph, it will show the # of Boomer voters rising into the future for another ten years or so (retirees who didn’t vote before retiring suddenly find the time and motivation to do so), then the senior citizen % of electorate continues to grow as the GenXers supplement the Boomers until they start to die off in the mid-to-late 2030’s, then rises slightly each year until the really big birth years of the early to mid 1950’s start to die.
It is excellent sport to explain all this to those rabid millenials who can’t wait for us to die off. They become incensed when you tell them that we will continue to have more political power than they will until they themselves are senior citizens. :-)