NAGANO — Last summer's historic victory by the Democratic Party of Japan in the Lower House election shook the national political structure to the core, including voting patterns.

The Liberal Democratic Party had long dominated the block votes of interest groups. For these organizations, it was important to support the ruling party to keep some influence in policymaking.

But times have changed and no one knows how long the DPJ will remain in power, or if or when the LDP will climb back onto the throne.