It happens this is also the answer to the problem posed in this article on the stagnation of culture:
Rewind any other 20-year chunk of 20th-century time. There’s no chance you would mistake a photograph or movie of Americans or an American city from 1972—giant sideburns, collars, and bell-bottoms, leisure suits and cigarettes, AMC Javelins and Matadors and Gremlins alongside Dodge Demons, Swingers, Plymouth Dusters, and Scamps—with images from 1992. Time-travel back another 20 years, before rock ’n’ roll and the Pill and Vietnam, when both sexes wore hats and cars were big and bulbous with late-moderne fenders and fins—again, unmistakably different, 1952 from 1972. You can keep doing it...The 1980s were the era when the Baby Boomers grew up, reached their late 30s and crossed into their 40s. They stopped wanting anything new about that time, and settled into middle age. The culture locked down with them, because the size of their cohort means that advertising, the movies, all the cultural industries look to them first and last.
Look at people on the street and in malls—jeans and sneakers remain the standard uniform for all ages, as they were in 2002, 1992, and 1982. Look through a current fashion or architecture magazine or listen to 10 random new pop songs; if you didn’t already know they were all things from the 2010s, I guarantee you couldn’t tell me with certainty they weren’t from the 2000s or 1990s or 1980s or even earlier. (The first time I heard a Josh Ritter song a few years ago, I actually thought it was Bob Dylan.)
If you were born in the 1980s, then, the world you know has never changed in any serious way. The political parties have always occupied the same basic positions: Reagan was the last sea change. You don't remember JFK, so Democrats have always been anti-war.
If this demographic trend is as suggestive as it seems to be, American culture will not change much for another twenty years or so. There are a lot of interesting things going on, but they're going on in corners: they'll not have a chance to influence the big show.