Electoral reform and the hope for change
In the early 1990s, growing dissatisfaction with corruption and stagnation led to electoral reforms. Japan introduced a mixed electoral system combining single-member districts and proportional representation, modeled in part to encourage a two-party system.
The goal was to bring accountability to government by increasing the chances of opposition parties winning, while strengthening the prime minister’s mandate. While this system did lead to some competitive elections and even brief transfers of power such as the Democratic Party of Japan’s (DPJ) win in 2009 the structural dominance of the LDP remained largely intact.
What didn’t change, however, was the pattern of frequent resignations. Since 1993, Japan has cycled through 13 prime ministers and many of them served less than a year. By comparison, Germany has had just three chancellors in that same period.
Why does Japan struggle to keep leaders in office?
One major reason lies in the architecture of Japan’s bicameral legislature, especially the power of the House of Councillors (upper house). While Japan’s Constitution makes the lower house (House of Representatives) superior in matters of legislation, a rejected bill can only be overridden with a two-thirds majority in the lower house — a high bar.
As a result, when the ruling party lacks control of the upper house — a scenario known as “divided government” — it becomes significantly harder to govern. In these cases, legislative deadlock, political brinkmanship, and public frustration all tend to rise, weakening the prime minister’s standing and often triggering resignations.
For example, in 1998, after the LDP lost an upper house election, Prime Minister Ryutaro Hashimoto was forced to step down despite holding the lower house majority. More recently, leaders like Abe Shinzō (during his first term), Fukuda Yasuo, and Kan Naoto were all pushed out during periods of divided government.
However, the upper house alone doesn’t explain everything. Leaders like Yoshir Mori (2000-01) and Yukio Hatoyama (2009-10) stepped down even with relatively stable parliamentary control.
Clearly, other factors are at play.
Factionalism within LDP
The LDP is not a unified ideological bloc but a collection of factions — informal, often competing power groups within the party. While factional politics have declined in influence since their heyday in the 1970s and 1980s, they still shape leadership contests and policymaking.
Prime ministers must constantly navigate these internal dynamics to survive. Unlike in more presidential-style systems, Japanese prime ministers are more dependent on party consensus and backroom support than on popular mandates.
When approval ratings dip — either due to economic missteps, scandals, or international miscalculations — factions may quickly withdraw their support, setting the stage for leadership changes.
This is what happened with Ishiba, who lost internal support after poor electoral showings and was forced out before a formal challenge could even be mounted. The new leader, Takaichi, inherits not just the position but the same unstable foundation.
AloJapan.com