Trump's commitment to build a wall along the 3145km border with Mexico and make the Mexicans pay for it seems wildly popular. Photo / Supplied
A narcissistic blowhard leads the Republican presidential race. A bearded weirdo leads the British Labour Party. Australia goes through prime ministers like a banana republic on fast-forward. What's going on?
While there's very little new under the sun, there do seem to be new factors at work, or perhaps factors that haven't counted for much in the past are now looming larger.
Old party loyalties are breaking down: It used to be the case in most Western democracies that the major parties of left and right had rock-solid support bases which would be there come election time regardless of leadership, policy orientation or circumstances.
Once upon a time you could pin a red rosette on a donkey and it would romp home in most Scottish electorates, but last year Labour was annihilated by the Scottish National Party. (In that context, Jeremy Corbyn's elevation to the Labour leadership has some logic.)
The Australian electorate, at both state and federal level, is now as fickle as a Persian cat. In 2012, Queensland Labor suffered the worst defeat by a sitting government in the state's history, winning just seven of 89 seats. Earlier this year a 14-point swing propelled Labor back into power.
Win the centre, win the election is the oldest rule of electoral politics. Easier said than done when the centre - the undecided vote - has expanded to the point that no one knows where it begins or ends.
Demographic and socio-cultural change: The days of young people voting a certain way because their parents did, and their grandparents before them, are gone. Young people today have different values and priorities and, like Henry Ford, tend to think history is bunk.
This week's Daily Telegraph got in a strop because Corbyn didn't sing God Save the Queen at a Battle of Britain memorial service. While that renders him unfit for high office in the eyes of the Torygraph's middle-class, middle-aged readership, I suspect most young Britons either didn't see it as a big deal or admired Corbyn for being true to his pacifist and republican principles.
The appeal of the anti-politician: Our culture's default position is that politicians are opportunistic if not venal and ineffectual if not hopeless. (Politicians have themselves to blame for this since they routinely portray each other as incompetent swine on a mission to make life worse for most of us.) Hence the appeal of mavericks and rebels whose basic pitch is a promise to break with politics as usual.
Stupidity: Embracing an anti-politician generally involves the willing suspension of disbelief or the inability to process basic information. Thus anti-immigration, pro-family values, fundamentalist Christians are going weak at the knees for a self-proclaimed philanderer on his third marriage. Like her predecessors, the current Mrs Trump is a trophy wife; like the first Mrs T, she's an immigrant.
Infantilism: There's a streak of childishness in current voter behaviour. The Greeks elected the Syriza party in the apparent belief they could escape the consequences of years of tax dodging, cooking the books and living beyond their means by sending arrogant young men to Brussels to harangue their European counterparts with Marxist claptrap.
Trump's only hard and fast policy commitment - to build a wall along the 3145km border with Mexico and make the Mexicans pay for it - seems wildly popular even though it's the sort of thing you'd expect to hear from a half-witted hillbilly mumbling into his moonshine.
The Obama factor: It's amusing that conservative US commentators, who in 2008 insisted Barack Obama had far too little experience in government to be considered presidential material, are endorsing the claims of Trump and retired neurosurgeon Ben Carson, neither of whom has held political office.
But with Obama's record looking more substantial by the month and the fact he's so much more of an adult than the vast majority of American career politicians, it's hardly surprising the electorate is discounting the value of experience.
Are there implications for New Zealand? We may be less susceptible to these convulsions because our much-derided MMP system acts as a safety valve through which frustration and silliness evaporate. However, it was dispiriting that Labour leader Andrew Little reacted to events across the Tasman with a schoolyard jibe at John Key. A more pertinent reflection would have been that, like Labour, Australia is on to its fifth leader in a short space of time and therefore difficult to take seriously.