Scholars sometimes speak of the presidentialization of parliamentary systems. Japan’s political constitution has been moving in this disrection since the election of Junichiro Koizumi in 2001. In the Japanese system, MPs of the leading parties function as a kind of “electoral college” choosing as Prime Minister NOT their de facto leader BUT rather someone popular with the voters for winning elections. Once elected, the populist PM has “authority” but lacks legal “powers” enabling him to keep his promise to voters. The executive power is vested in the cabinet. Thus, the PM is “checked & balanced” by his colleagues (cabinet ministers and ruling party’s MPs) on the political level and by bureaucratic officials on the administrative level.
The PM can hire and fire his ministers but has no power to “control and supervise” them. Though the PM may overcome this constraint by using his authority to directly appeal to the people (by threatening to dissolve the Diet), such a move is politically risky if a certain number of ministers/ruling party MPs are opposed to him (or his policy). Ironically, A PM who heavily relies on his “democratic authority” is considered to abuse of power and therefore becomes unpopular among the ruling party members.
The PM can control and supervise the administrative agencies, but has no power to appoint or remove agency officials. On this level, he is confronted by varied corps of bureaucrats constituting the permanent national government. This national bureaucracy, which holds the power to interpret the laws, draft bills and make policies, is highly autonomous. The PM does have powers as supreme organ of public administration, but by exercising PM’s administrative functions he degrades himself to “chief bureaucrat”; that is, the PM can trump bureaucracy only if his orders follow non-political, “neutral” norms shared by the bureaucratic part of the central government. It is the legal relations among organs of administrative bodies, NOT democratic authority, which rules the public administration. Besides, agency officials can oppose to the PM’s policies through ministers and mass media speaking for them. All these factors create a system in which the PM reigns but does not rule.
This quasi-presidential system creates tensions between the PM and ruling party. The populist PM is no more willing to cooperate with partisan politics inside the Diet, instead placing his legitimacy in the non-partisan “sovereign people”. He decides the agenda to be discussed in the election. If he wins, the PM tries to keep his promise by imposing the newest people’s command on partisan MPs, raising tensions between factions or parties. If he loses in upper-house elections, he will lose his control over his party. In the former case, the problem is that the people know little about constitutional restraint of PM’s power. They will withdraw their support if the PM fails to keep his word. As to the latter case, PM has little choice: either he goes back to play partisan politics (inside the ruling party or between the parties) which he is not good at, OR he relies on the non-partisan public administration to regain non-partisan popular support. In either case, PM will be politically weakened in the bargaining process- and the populist voters usually don’t want to see any bargain.
–Tokujin Matsudaira, Hitotsubashi University