London's Mayor-elect, Boris Johnson arrives at City Hall to sign the "Declaration of Acceptance of Office" for the Mayor of London, in central London on May 3, 2008. (UPI Photo/Hugo Philpott)

LONDON, May 5 (UPI) -- The victory of Boris Johnson in London's mayoral election represents the emergence of a new generation of politicians into the struggle for power. The baby boomers are starting the long, sad slide into senescence. The generation X-ers are on the march.

The first sign of this great shift came in Russia earlier this year when Dmitry Medvedev, at 44 just two years older than Johnson, succeeded Vladimir Putin as president. The crucial sign will come in the United States later this year, where uniquely all three generations are battling for the presidency.

As well as Sen. Hillary Clinton, the classic baby boomer, and the young upstart Sen. Barack Obama, the classic generation X-er (and son of a restless and globe-trotting baby-boomer mother), Sen. John McCain represents the Silent Generation.

Born in the Great Depression of the 1930s to a career Navy officer and thus a member of what Americans now call the greatest generation for their wartime feats, McCain falls into that gap before the coming of the baby boomers that is known as the Silents. They were the ones who came of age in the 1950s, that period of American conformity and the anti-Communist witch hunts of the McCarthy era.

It has always been unfair to call this generation the Silents, when they produced the beatniks, rock 'n' roll, Elvis Presley and Margaret Thatcher, and launched the civil rights movement in the United States. And few of them were less silent than the rowdy, rebellious and trouble-making fighter pilot McCain.