The Census reports that there were more 22-year-old Americans in 2013 than any other single age — making it the first time a non-Baby Boomer age has been the most populous since the Baby Boom began.

But for those watching for the political implications of this sizable shift (or perhaps boning up on their Britney Spears trivia in preparation), don't expect big changes yet -- if ever.

It's not as though you'll suddenly encounter more people born in 1991 than 1961 as you go about your day. These are estimates; the Census Bureau's full decennial count last occurred in 2010. Are there more 22-year olds than 53-year olds, the group that was otherwise poised to take the top spot? We'll never be entirely certain, but given that the dominance of the Boomer generation (those born between 1946 and 1964) was necessarily going to end at some point, this is as good a marker as any.

We compiled "single year of age" data from the Census Bureau back to 1900 (largely from this Web page), and you can see two interesting patterns emerge in a graph of the age that was most common for each year.

First: Prior to 1925, the most populous age hovered around zero. People were born and populations faded after that. Then, after World War I, the most populous age got larger (i.e. older) continuously — until the series of baby booms that mark the Baby Boom proper. Since about 1962 -- the last such boom -- the most populous age has risen fairly continuously, until 2012. (As The New York Times points out in its analysis, there are different counts the Census Bureau uses. The counts below are the resident population.)

Back to the politics. The first year a Millennial age outnumbered any of the Boomers (according to the estimates) was 2012, when 21 became the most populous age. In 2012, something else happened: It was the first time since 1976 that Boomer voters picked the losing candidate in a presidential election. We looked at exit poll data compiled by the University of Connecticut's Roper Center to put together the table below. The age groups listed were those that voted the most heavily in each election, according to exit polls. In each case, that group overlapped with the Boomer generation.

Election Highest voting age group Preferred candidate Margin preferred by
(percentage points)
1976 30-44 Winner 4
1980 30-44 Winner 17
1984 30-49 Winner 16
1988 30-44 Winner 8
1992 30-49 Winner 3
1996 30-49 Winner 9
2000 30-49 Winner 2
2004 30-49 Winner 7
2008 40-64 Winner 13
2012 45-64 Loser 4

This is the sort of thing that keeps Republican strategists up at night. As the Boomers age and become a smaller (but still large) percentage of the population, younger voters — who swept Obama into office in 2008 and who backed him by a 23-point margin in 2012 — will be more of the voting base.

Earlier this year, Pew Research released analysis showing that Millennials tended to be more socially liberal and more likely to vote Democratic. But as NPR (and others) pointed out, the picture is murky. It's not clear how loyal Millennials will be to the Democratic Party, if at all. In fact, they were more likely to reject party labels than older generations.

More interestingly, the Millennial generation isn't going to be a second boom. Instead, it will likely be a point in what Pew Research once called the "U.S. age rectangle," the end of sharply tiered age groupings. The Census Bureau estimates that the 2050 population will be distributed something like this:

There will still be Boomers around, but the Millennials that lead the pack right now are mixed in at about the same rate as the generations that follow. (And, again: They barely lead the pack right now.) Owning the Millennial vote, in other words, wouldn't mean a whole lot in terms of electoral dominance over the long term.

So what does it mean for politics? We'll leave that to the party strategists to assess. We're clear on what it means for pop culture, however: a lot more That's So Raven and Pokemon references. Buckle up.