Six years have passed since the Democratic Party of Japan government, which was regarded as center-left, stepped down and the Abe administration of the Liberal Democratic Party-Komeito coalition came to power. Far from reconstructing itself, after falling from power the DPJ broke up. Core members of its left-leaning factions have now formed the Constitutional Democratic Party of Japan. But the party’s approval rating remains stagnant, hovering around 20 percent of that of the LDP.

In the United States, it is said that in the mid-term elections to be held in November, the Democratic Party has a strong chance of winning a majority in the House of Representatives. But the party has not yet found a candidate who can stop the re-election of President Donald Trump, who won the 2016 race by shunning political correctness. In European countries, the social democratic forces that constitute the center-left are suffering from a conspicuous decline, while the ultra-right parties are growing stronger.

Amid this trend, a widening of income inequality in Japan, the U.S. and Europe is gaining attention. Originally the left attached importance to income redistribution policy aimed at reducing income inequality. As such, it is logical that the left should get more political support, but the opposite is happening.

Why is the center-left suffering a decline? Of course, each country has a peculiar reason for this, but there seems to be a common political and economic background that transcends these individual situations.

The first factor is a structural change in the world economy, which is referred to as an elephant curve. A representative explanation for the change was given by Branco Milanovich, a U.S. economist who pointed to a change in global income distribution. In and after the 1990s, a period in which progress was made in economic globalization and the income of the wealthy and middle classes in developing countries rapidly increased. In contrast, in developed countries, while the income and assets of the wealthy class increased, the income of the middle class and lower classes stagnated.

If we plot household income levels on a horizontal axis (starting with the poorest and ending with the richest) and the growth rate for each income level on the vertical axis, we end up with a graph that looks like an elephant as seen from its right side.

The tip of the trunk high up on the right side represents most of the wealthy class of developed countries, while the base of the trunk represents the middle class and those below the middle class in developed countries. Meanwhile, the swelling head represents the high- and middle-income classes of developing countries.

In this situation, an increasing number of people, especially those of the middle class in developed countries, have come to fear the rise of the economies of China and other emerging countries and an influx of immigrant labor. This sentiment has been accompanied by nationalism and hostility toward immigrants and moves toward protectionism are intensifying. They are fueling the increase of populism.

Since the traditional center-left has opposed discrimination based on race, ethnicity, religion and gender, and has respected the liberal spirit — which is tolerant of diversity — it does not fit in with the exclusivist moves against immigrants. This is seen typically in the U.S.

But the real picture is not so simple as to mean that all leftist forces are tolerant of immigrants. In Europe, it appears that there are not a few cases in which the left is silent about the most difficult problems — those centering around immigrants and refugees. Even so, against the backdrop of the rise of exclusivist views that fan fears of threat over economic and security issues, domestically dissatisfied people seem to be inclined to support parties of the right rather than center-left parties.

The second factor behind the decline of the center-left is the fact that liberal values, which oppose discrimination based on race, ethnicity, religion, gender and other points, have spread in developed countries’ legal systems and social customs in the postwar period. As a result, ironically, being liberal no longer means being radical or provocative.

In the past, when illiberal laws and custom were prevalent, liberal contentions by the left offered youths — who were too proud to adapt themselves to a society dominated by adults — a theoretical weapon for protest. But ironically, as society in reality becomes liberal, the power of the left’s contentions to attract young people appears to have weakened.

In addition, the most extreme leftist forces in Western countries, which grew out of the Marxist current, have almost broken up due to the collapse of the Soviet Union and the Chinese economy’s transformation into something like state capitalism. The left in Japan and Western Europe has lost its grand vision of regime choice between capitalism and socialism.

In other words, the center-left has lost the far-left pole of socialism and communism, and simultaneously its bearings to counter the right has become blurred as real society has become liberal.

But it must be pointed out that the current situation characterized by the rise of the far-right and populism is also a threat to the center-right. In Japan, the number of people who support no particular political party has dramatically increased. In the U.S., Trump, who is utterly different from the Republican Party’s mainstream, has caused a disturbance in the centrist forces of the GOP. In Britain, a proposal to exit the European Union unexpectedly triumphed in a referendum.

It can be said that parties on both the left and right in developed countries have entered into a chaotic age in which they are looking for new political axes.

Masaharu Takenaka is a professor of economics at Ryukoku University.