For the last 50 years, almost every U.S. presidential election has brought a new swing of the national political pendulum. Richard Nixon's shifty administration gave way, after Gerald Ford was in office long enough to pardon his former boss, to the choirboy Jimmy Carter.

Four years later, in rode Ronald Reagan and then, following George H.W. Bush's one-term interregnum, came America's first baby boomer president, Bill Clinton.

An impeached (but brainy) philanderer, Clinton was succeed by Bush's son, the moralizing and anti-intellectual George W. Bush, who then gave way to the Spock-like Barack Obama, before the pendulum's widening swing extended all the way to the unprecedented fringe of Donald Trump.