Jacob Zuma and Donald Trump get matching bruises in a new book about the threats to democracy around the world.

After studying five young democracies and two established ones‚ Professor Ursula van Beek of Stellenbosch University says South Africa is “struggling in the aftermath of the ruinous rule by former President Jacob Zuma”.

While Van Beek criticises populists such as Zuma‚ she finds herself on the same side of the globalisation argument as the US president‚ who told the UN General Assembly on Tuesday: “America is governed by Americans. We reject the ideology of globalism and we embrace the doctrine of patriotism.”

Van Beek‚ editor and co-author of “Democracy under Threat: A Crisis of Legitimacy?” said: “Democratic nation-states are no longer fully in control of their own economies as they are tied into – and rely on – the global economic system.”

This exposed citizens to more severe economic and social risks and increased inequality. “Global technological advances call for highly skilled individuals [who] are more mobile and generally financially better off than their less skilled fellow citizens who have fewer job opportunities ... This disparity evokes resentments that can lead to populism.

“The rise in populism is also a response to the growing inflow of migrants and refugees‚ which the open borders of democratic nation-states facilitate‚” said Van Beek‚ founder and director of the Transformation Research Unit in Stellenbosch’s political science department.

“The populist tendencies have spread even to the most established democracies; the election of Donald Trump ... is a good example of people who feel marginalised and who are thus ready to support a populist candidate promising them a better life.”

The book‚ with contributions by leading researchers across the world‚ says populists are not anti-democracy. Instead‚ they “erode the liberal values of democracy through their rhetoric and attempts to undermine liberal institutions to better serve their own ends”‚ said Van Beek.

Van Beek and colleagues focus on five young democracies — SA‚ South Korea‚ Chile‚ Poland and Turkey — and the well-established democracies of Germany and Sweden.

On top of SA’s Zuma struggles‚ Turkey had become an authoritarian state and Poland had a populist leader. “The three countries have suffered a setback to their democracy‚” said Van Beek.

“In the process‚ South Africa has experienced a rise in radicalism between 1995 and 2013‚ with support for democratic rule declining and support for non-democratic rule on the increase.”