The surprising triumph of maverick reformer Junichiro Koizumi as leader of the Liberal Democratic Party and prime minister of Japan could ironically wind up sabotaging hopes for periodic changes in the nation's government.

For years, political analysts and opposition leaders have been predicting that a grand realignment of politicians would create a new force capable of heading the government and given Japan a two-party political structure. The spark for such an upheaval, the analysts insisted, would be another rebellion in the LDP similar to the one in 1993, when a party split drove it out of power for 10 months.

Koizumi's victory, however, has eliminated the possibility of a realignment, at least for the foreseeable future.