China's rubber-stamp parliament, meeting in the imposing Great Hall of the People for an annual session, made Xi the most powerful leader since Mao Zedong on Sunday by scrapping term limits that would have forced him to step down after 2023.
The decision moves one-party China further away from adopting a democratic system that many Western thinkers and politicians had once assumed was inevitable as the country opened up to global trade.
It fits a pattern worldwide that has seen the model of liberal democracy -- based on individual rights, the rule of law and the free press -- lose ground as many countries turn instead to more authoritarian forms of government.
"We think it (liberal democracy) is normal and obviously it's not, because in the whole of human history, democracy has not existed for all that long in terms of the international order," said George Magnus, associate at the China Centre at Oxford University.
Regimes with illiberal leaders "reject the kind of democratic model we have kind of grown up with," he added.
These include Vladimir Putin of Russia, Turkey's Recep Tayyip Erdogan, and the Philippines' Rodrigo Duterte, who all came to power through the ballot box but have since trampled democratic norms.
Other global contemporary strongmen include Egypt's Abdel Fattah al-Sissi, who took part in a coup against a democratically elected Islamist government.
"It is certain that the club of managed (or guided) democracies is growing," said Caroline Galacteros, director of the Planeting strategic intelligence consultancy in France.
In Europe, Hungary's Viktor Orban has become a posterboy for what he calls a form of "illiberal democracy" while US President Donald Trump also embodies a spreading strain of aggressive nationalism worldwide.
Trump's "America First" mantra and attacks on institutions such as the FBI, the judiciary and the free press are testing the democratic checks and balances in the US constitution.
- Chinese model -
Human rights campaigners warn that authoritarians and autocrats worldwide are exploiting discontent over globalisation, industrial decline, terrorism and migration to justify their actions.
According to the Freedom House human rights watchdog, democracy "faced its most serious crisis in decades" in 2017, which was the 12th year in a row that individual freedoms were found to have declined.
Furthermore, under Trump the US has lost the moral authority to effectively condemn abuses in other countries, critics say, while Europe is struggling with its own nationalists in Hungary and Poland.
- 'Managed democracies' -
In the 1990s, intellectuals such as Francis Fukuyama questioned whether humanity had reached the "end of history", with liberal democracy and capitalism apparently victorious over communism and totalitarianism.
But by the turn of the century, analysts were warning of the emergence of semi-authoritarian states -- countries that like Turkey and Russia fall somewhere between democracy and dictatorship.
China's trajectory was always unknown, but the country has taken a decisive turn away from the idea of a more pluralistic society with greater political freedoms.
And, thanks to its fast economic growth and growing military might, it is serving as a counter-example for the democratic model -- with fans in sometimes surprising places.
"The great leaders of the world come from countries that are not great democracies," said former French president Nicolas Sarkozy at a conference in Abu Dhabi last weekend.
Sarkozy, who faces multiple investigations over corruption allegations related to his one term in office from 2007-2012, said strong leadership in China, Russia and Saudi Arabia meant there
was "no populism" there.
Kenneth Roth, director of Human Rights Watch, said democratic leaders have a responsibility to speak out against autocracies and despots who depend on large-scale repression to keep their grip on power.
"It is important for democratic leaders both to highlight the emptiness of the autocrats' political programs and to stress the danger of enabling leaders who claim to speak for the majority," he said.
"China has been providing economic support to autocrats around the world and increasingly is trying to silence criticism of its own autocratic model even within liberal democracies."
He cited Beijing's close financial links to repressive regimes in countries such as Venezuela and Zimbabwe.