The sharp defeat for Japanese prime minister Shinzo Abe in Sunday's upper house elections was widely anticipated in opinion polls but is more far-reaching than expected. The setback will colour his remaining two years in office before the next general elections must be held - if, that is, he survives until then as leader of the Liberal Democrat Party. This is the first time it has been defeated by a single opposition party since 1955. Similar setbacks in 1989 and 1998 forced the then prime ministers to resign.
Mr Abe succeeded the popular Junichiro Koizumi in the office last September, inheriting a large majority secured in 2005 by the LDP in the more powerful lower house of parliament. He campaigned on a nationalist platform, pledged to restore patriotism in the educational system, boost the military's morale and international involvement and end the post-war regime which has constitutionally limited that role. At 52, he was the first prime minister to be born after the war. Coming from a well-known political family, he was expected to have the skills needed for the job - and certainly displayed them effectively in his initial dealings with China and the United States.
But no comparable deftness of touch has been on display in the domestic arena. A series of corruption scandals and public gaffes dogged cabinet ministers and senior officials, culminating in the agriculture minister's suicide in May over falsified expenses and rigged contracts.
Mr Abe's judgment and authority gradually came into question as these woes accumulated. Such suspicions were spectacularly confirmed in June when the government admitted losing 50 million pension records and Mr Abe appeared slow and casual about assuming responsibility and taking decisive action on it. Japan's rapidly ageing population is appalled by what happened, since many people now do not know whether they will qualify for their entitlements.
Mr Abe failed to reassure them during the campaign and the result shows how important that mistake has been. It confirmed the impression that social and welfare issues take second place for him behind constitutional and foreign policy ones.
His party lost heavily in rural areas which it has always dominated, while throughout the country LDP voters are shifting support to the centre-left Democratic Party of Japan, despite its inexperience, in order to encourage a more competitive two-party system. Mr Abe insists he will not resign. But unless he rapidly re-establishes his authority and credibility he will become another stop-gap LDP leader and prime minister, not the strategic begetter of change he set out to be.