My realtalk buddy brought up something I hadn't thought about before. He said the transition from Bush I to Clinton was abrupt because there was a 22-year difference in their birth years. Here is a list of Presidents that includes their birth year.
Clinton was the first Boomer president, beginning a reign of at least 24 years of that generation. It's odd that there doesn't seem to be random variation across generations, but that they're all from a single generation.
Had that happened before? In fact, starting with John F. Kennedy in 1961, there was a 32-year reign of Greatest Gen presidents, with 16 years separating the youngest from the oldest. And it was not a simple story of later-born members succeeding the earlier-born. Johnson was older than his predecessor Kennedy, and Reagan was older than Carter. It didn't go in reverse order either, as Nixon was younger than Johnson, Ford younger than Nixon (by less than a year), Carter younger than Ford, and Bush I younger than Reagan. It's as though voters wanted somebody from the Greatest Gen to lead the country during the '60s, '70s, and '80s, and it didn't matter where exactly in the generation they were born.
Fun fact: there's a 2-year period from January 1987 to January '89 when all major leaders were Greatest Gen -- Reagan as President, Bush I as Vice President, Robert Byrd as Senate Majority Leader, and Jim Wright as Speaker of the House.
Notice the total lack of Silent Gen presidents -- guess they had them figured out back in 1951. And it's not for lack of contestants either -- Mondale, Dukakis, Perot, Kerry, and McCain were all Silents, spanning the entire generation from the second half of the '20s to the first half of the '40s. Yet all lost. In the next election in 2016, the youngest of them will be in their 70s, which is not unheard of, but still makes it highly unlikely that there will ever be one. (Drawing the contemporary analogy, hopefully that means that we'll never be ruled by a Millennial president.)
Again we see that it's not a simple story of succession of one cohort after another, or the Silents would've been in there at some point.
By the way, Silents have snuck into lesser offices. Five terms of Vice Presidents have been filled by them (Mondale, Cheney, and Biden). For 23 years off and on since the early 1980s, a Silent has been the Senate Majority Leader (Baker, Mitchell, Lott, and Reid). And from June of 1989 to January 2011, the Speaker of the House was a Silent. This last office seems to show the simple story of gradual succession of birth cohorts. It is also the least symbolic.
Before the Greatest Gen reign, there's a 28-year block of presidents born from 1880 to 1890, before the quantum leap to Kennedy.
Earlier still, there's a 32-year stretch from Theodore Roosevelt to Hoover, who were born within 18 years of each other, although it was not such a huge jump from Hoover to FDR.
But there is another big gap before Theodore Roosevelt, who was 15 years younger than his predecessor McKinley, who himself was part of another block going back to Grant who were born within 21 years of each other.
Then another big gap between Grant (1822) and Johnson (1808), who is part of an earlier 28-year block of births from the early 1800s and late 1700s, going back to John Tyler (1790), with Zachary Taylor (1784) being the only outlier in the block.
I don't pretend to know what any of this means, but it's worth looking into quantitatively, and more importantly trying to figure out what leaves certain generations in or out, and when they are in or out of demand. There is a pretty clear link of the timing of the blocks to the timing of the crime rate -- the rising-crime period of circa 1900 to 1933, the falling-crime period from then until 1958, the rising period from then until 1992, and the falling period since.
Rising-crime times select presidents who spent most of their childhood and perhaps adolescence in an earlier rising-crime period -- in particular, near the end / peak of the wave of violence. Theodore Roosevelt through at least Harding were born near a peak of violence in America that is most familiar from the Civil War (although it's not helpful to think of episodic wars as defining events, but the year-to-year trends of which they could be a part). Silent Cal and Hoover may have been born a little too late to experience that wave as children, but I'm not totally sure.
But FDR, Truman, and Eisenhower definitely were. They were children during the Gilded Age, though Eisenhower as an adolescent experienced the very beginnings of the early 20th-C. crime wave. Overall, though, not that much exposure to rising crime while growing up, and certainly not during phases of the crime cycle that are near the peak. This is the generation thought best to lead during the falling-crime mid-century era. We don't need a wild child like Teddy Roosevelt anymore, things have calmed down, and someone whose formative years were during the calm Gilded Age seems more appropriate.
Once the crime rate began climbing in 1959, voters thought it was time for a change -- someone whose formative years were marked by soaring violence levels and gangster rule, who might have some kind of intuition about how to handle the problem. So all of the sudden, people who grew up during the 1910s and Roaring Twenties (which lasted into the early '30s), were the right people for the job.
As crime rates peaked in 1992, voters were ready for a return to presidents whose formative years were in calmer times. People who grew up in the post-War, Dr. Spock, Leave It to Beaver world. Obama is somewhat of an anomaly in that respect, though his early years were only at the beginning of the crime wave. The second half of a crime wave feels qualitatively different than the first half -- compare 1959 through 1975 vs. 1976 through 1992. So again it may relate to growing up closer to the peak of the wave.
When crime rates begin rising sometime around 2020, we'll probably choose a president from Generation X, who may be around 50-55 years old, or perhaps one of the rarer young presidents if he's born into the '70s. (Of course I could be off by an election.) I predict we'll stick with Gen X presidents all through the next crime wave, just as we stuck with Greatest Gen presidents during the last wave.
And when things calm down, it'll skip the Millennials, whose sheltering during their formative years will keep them from seeming right for the highest office. It'll make another quantum leap to whatever the generation after Millennials will be, some of whom may already be born but not more than about 5 years old yet. They'll have grown up mostly in the post-9/11, neo-Dr. Spock, Return of the Leave It to Beaver world, but also have some adolescent experience with the coming crime wave.
People grossly underestimate the importance of a person's formative years -- they don't call them that for nothing.