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.