“There are decades where nothing happens; and there are weeks where decades happen”, said Vladimir Ilyich Lenin, and so it was last week, starting with the attempted assassination of Donald Trump and ending with Joe Biden pulling out.

Biden’s decision was inevitable – the pressure had become too great, and even he couldn’t ignore the obvious fact that after the debate he had become unelectable.

His announcement means that the Democrat nominee will now be chosen at the convention that begins on August 19 rather than through the primaries, which he won.

And Biden’s endorsement of vice-president Kamala Harris means that it’s hers to lose.

She may even stand unopposed at the convention: one potential rival – Michigan Governor Gretchen Whitmer has already dropped out.

So the question now is whether Kamala Harris is electable, or rather electable enough to defeat Donald Trump, who is almost as old and confused as Joe Biden.

Which is why the Republicans’ succession planning with the choice of 39-year-old millennial JD Vance, along with the party’s apparent discarding of neoliberalism, is so significant.

Trump won’t stand aside, but Americans who vote Republican will know they are also choosing their candidate for 2028, and given Trump’s own evident cognitive decline, Vance could well become president before then.

Harris is 59 and will be 60 when she is inaugurated next year, if she is nominated next month and then wins. Her likely running mate, transport secretary Peter Buttigieg, is three years older than Vance.

The 2024 US presidential election was always going to be a turning point for America and the world, but the sudden withdrawal of Joe Biden and the appointment of JD Vance as the future of the Republican Party has made it even more so, not to mention fascinating.

Unlike Trump’s, Vance’s speech to the Republican convention last week was a powerful, carefully constructed one, and when he said “We’re done, ladies and gentlemen, catering to Wall Street. We’ll commit to the working man”, not only did he mean it, the party cheered.

Kevin Roberts, the president of the right-wing Heritage Foundation and the driving force behind Project 2025 – the organisation that is preparing for a full takeover of the civil service once Trump is president – said that Vance “is absolutely going to be one of the leaders — if not the leader — of our movement.”

It’s always possible that Trump will sideline Vance like he did Mike Pence, which is the fate of most VPs (except, perhaps, Dick Cheney), but let’s take his speech at face value. What might end up being called Vancism is still evolving, but at this stage the intellectual foundation of the movement that he unexpectedly leads is a combination of cultural conservatism and government activism.

It is the natural home for poor working-class Christian conservatives who were left behind by neoliberalism’s focus on the free market and, with the benefit of hindsight, it was the inevitable destination of Trump’s brand of populism.

If Trump and Vance win, climate change policies will be abandoned and other totems of cultural conservatism will be embraced, like abortion restrictions and opposition to diversity and inclusion.

The market is no longer viewed by them as the best way to run an economy, with the state seen as better at directing resources.

There will be greater protectionism, restricted immigration and America first procurement. Whether Trump and Vance take the further step of enforcing greater controls on the labour market and make housing and healthcare a right rather than a privilege for the wealthy, is harder to predict, but not out of the question.

They will probably have to match tariffs with greater central control of wages, as Australia did with the Harvester Judgement of 1907, and while it’s hard to imagine either Vance or Trump becoming some kind modern-day FDR with a conservative version of the New Deal, it looks like his state activism will be part of their administration.

Franklin D Roosevelt set the global political consensus for four decades until Milton Friedman killed it with neoliberalism, which then lasted another four decades. It was coming to an end as a result of the pandemic and the government intervention that entailed, but is dying hard.

Many of the things that made America great are gone, as the MAGA slogan assert, but one source of its greatness continues: Silicon Valley, and the utter dominance of global technology by the Magnificent Seven companies, something we were reminded of on Friday.

So maybe Trump and Vance would emulate that earlier Republican, Teddy “Trust Buster” Roosevelt, who broke up the railroad, oil and tobacco monopolies, and break up the big tech oligopoly, which would certainly achieve their other aim of bringing down the US dollar and lead to the rebirth of manufacturing, which is what they believe is needed to make America great again.

It would also cause a stockmarket crash, but they are apparently done catering to Wall Street.

A day after Vance, Donald Trump took to the convention stage, also with a prepared speech that had been billed as a call for unity and calm, but he couldn’t stick to it, and soon wandered off script into a long rambling rant that did the opposite, full of grievance, enmity and lies.

It went for 90 barely coherent, minutes, with 25 million people watching. He is his own worst enemy, and with a half-decent opponent, he should lose … again.

Can Kamala Harris beat him? That is now the question, and stakes have been raised immeasurably by the Supreme Court’s ruling on July 1 giving the President unconditional legal immunity for “core decisions” made in office, and partial immunity for many others.

As Justice Sonia Sotomayor wrote in her dissent: “In every use of official power, the President is now a king above the law.”

A lack of legal accountability for the US president is nothing new, but before now it has only applied outside the United States.

American presidents have waged illegal wars, toppled democratic governments and assassinated foreign leaders, illegally detained tortured people, and supported repressive regimes without any legal liability in domestic or international courts.

The Supreme Court’s decision makes the president’s actions within the US as unconstrained as they are outside it.

The idea of giving that power to a man who is what former Republican house speaker Paul Ryan calls an “authoritarian narcissist”, makes this election – more than any in history – a turning point for America, and the world.

Alan Kohler writes weekly for The New Daily. He is finance presenter on the ABC News and also writes for Intelligent Investor.