SANTIAGO – From Austria, France and the United States, to Poland, the Philippines, and Peru, illiberal populists are on the rise. Some blame runaway globalization; others blame income inequality; still others blame out-of-touch elites who simply don’t get it.

Such explanations – however plausible they may be – miss the larger point. The problem is political, not just economic. Liberal democracy is humankind’s greatest political achievement. Yet liberal democrats around the world are reluctant to make the case for it. No wonder they are losing the battle for citizens’ hearts and minds.

The problem is far from new. In fact, it is at the very root of liberalism. Wary of censorship or oppression, liberal thinkers have more often than not espoused moral neutrality: they do not advocate a single set of values, or a particular definition of what constitutes a good life. A liberal society – almost by definition – enables its citizens to lead any life they wish, as long as third parties suffer no harm.

The problem is that politics everywhere is Aristotelian: concerned with virtue. Americans refer to their presidency as a bully pulpit with good reason. When politicians advocate a particular set of values – or virtues – voters listen.

This can be done clumsily, as when John Kerry accepted the Democratic Party’s presidential nomination in 2004 with a speech that repeated the word "value” or "values” 32 times. But it can also be done magisterially, as when Robert F. Kennedy Jr. chided Americans for surrendering "personal excellence and community values in the mere accumulation of material things.” GDP, he memorably added, "measures everything (...) except that which makes life worthwhile.”

Philosophers from John Stuart Mill to John Rawls to Martha Nussbaum have sought a way out of liberalism’s quandary. It would be discriminatory and illiberal to promote, much less impose, a particular group’s values, religious or otherwise. But governments and political leaders can and should advocate the shared values – what Rawls called the "overlapping consensus” – that define a liberal society. By commemorating Martin Luther King Jr.’s birthday, for example, the US both underscores and rededicates itself to the shared ideal of racial equality.

It was King himself who arguably provided the best example of the passion with which such ideals can (and should) be defended. There are too few like him. Populists like Donald Trump and French National Front leader Marine Le Pen use passion in the service of a politics of fear and hatred. By contrast, liberal democrats, products of the Enlightenment all, advocate for their political ideals – which value human reason above base emotions – in a tone best suited to small, polite gatherings.

This is a serious problem. "Ceding the terrain of emotion-shaping to anti-liberal forces,” writes Nussbaum, "gives them a huge advantage in the people’s hearts and risks making people think of liberal values as tepid and boring.”

Reason and emotion, neuroscientists like Steven Pinker tell us, are two sides of the same mental coin. Likewise, cognitive linguist George Lakoff, drawing on work by psychologist Drew Westen, concludes that "emotion is both central and legitimate in political persuasion. Its use is not an illicit appeal to irrationality, as Enlightenment thought would have it. The proper emotions are rational.”

King understood this very well when he proclaimed his "dream” of a society in which his children would "not be judged by the color of their skin but by the content of their character.”

Today, US President Barack Obama is the only liberal democratic leader who speaks the language of values and virtue. Obama is often criticized for being cool and aloof, and yet there is nothing of the sort in his promotion of the capacity to live together in peace and mutual respect as the most admirable liberal virtue of all.

"Each of us has deeply held beliefs,” he said in his victory speech in 2008. "And when we go through tough times, when we make big decisions as a country, it necessarily stirs passions, stirs up controversy,” which he called "a mark of our liberty.” And yet, "despite all our differences, most of us share certain hopes for America’s future...We believe in a generous America, in a compassionate America, in a tolerant America open to the dreams of an immigrant’s daughter who studies in our schools and pledges to our flag.”

That last line reveals that Obama is also aware of the other challenge liberal democracies must overcome: to shape a credible us. The populists’ example is again telling. Right-wing populists such as Trump engage in identity politics. Left-wing populists such as Bernie Sanders engage in income politics.

Andrés Velasco is Professor of Professional Practice in International Development at Columbia University’s School of International and Public Affairs.

Copyright: Project syndicate