The Baby Boomers were, until recently, the largest generation in American history (at 78 million). They dominated American life and culture for more than 50 years - as the first kids raised on TV in the 1950s, the disruptive peaceniks, Vietnam warriors, and crewcut Nixon bully-boys of the 60s, discoteque denizens of the 70s, yuppie 30-somethings in the 80s, the soccer moms and Nascar dads of the 90s, and now the targets of endless Dennis Hopper commercials for retirement accounts. They remain the dominant cohort in the workplace, where their grip on the executive corridor may last another 10-15 years.

But in Presidential politics, they are done.

One of the more remarkable outcomes of this year's political season is that we have somehow arrived at two major party candidates who straddle the far ends of the generational divide. John McCain, age 71, stands as the last hope of the Silent Generation - the only generation in American history never to elect a President (they had their best shots in 1968 with Robert Kennedy and 1988 with Michael Dukakis). And of course Barack Obama, age 46, counts either as the youngest Boomer or the first GenXer, depending on where you draw the line.

Between them, they ushered quite an array of Boomer political talent off the stage, from the estimable Senator Clinton to such Boomers-of-the-right as Mitt Romney and Mike Huckabee. On the Democratic side, the close race fractured almost neatly along generational lines, with the leading edge of the Millennial generation putting their heavy thumb on the balance for Obama. His nomination, even if it does not result in victory in the fall, caps the first mobilization of this new voting cohort and portends a long era of civic-progressive dominance in American politics, at least according to Morley Winograd and Michael Hais (authors of Millennial Makeover: MySpace, YouTube & the Future of American Politics). Among  Republicans, you can't exactly say there was a yearning for McCain's somewhat more deliberative and conciliatory style, but the surfeit of combative and ideological Boomers in the race seemed to cancel each other out, leaving McCain the last man standing.

In both cases, the nominations seemed to represent a basic public exhaustion with the dramatic, conflict-prone, and piercingly ideological quality of the Boomer era, which began with the election of Bill Clinton in 1992, accelerated with the arrival of the Republican congressional majority in 1994, and reached its apogee in the post-9/11 Bush era. It's ironic that many Boomers like to point to political activism as a key component in their historical legacy, but when they got their turn at leadership, the best they could produce were Bill Clinton and George W. Bush.

Here's hoping that 2009 sees the dawn of a new generational era in American politics, which, having risen from humbler beginnings, soars to greater heights.