As the limitations of Prime Minister Junichiro Koizumi's government reveal themselves, there are emerging signs of the possible downfall of his Cabinet. The crushing defeat of a Liberal Democratic Party candidate in the Upper House by-election in the Niigata constituency on April 28 was one event testifying to this. Mass media noted that the victory of the LDP candidate in the Lower House by-election in Wakayama Prefecture on the same day, coupled with the victory of the opposition candidate in the Tokushima gubernatorial election, gave LDP one win and two losses.

The gubernatorial election aside, both Wakayama and Niigata have long been LDP strongholds. The Niigata defeat, especially, must have dealt a heavy blow to the LDP, as it has been an impregnable conservative fortress since the days of the late former Prime Minister Kakuei Tanaka, the father of former Foreign Minister Makiko Tanaka.

Obviously, Koizumi's "sacking" of Tanaka as foreign minister on Jan. 29 seriously affected the by-election in Niigata. Until then, Koizumi had enjoyed a high public-approval rating of more than 80 percent, but his popularity there has since plunged to below 50 percent. This indicates that Tanaka had contributed to more than 30 percent of Koizumi's popularity ever since his government began a little more than a year ago.