That Yamada Masahiko should be the leader of the opposition to the Trans-Pacific Partnership now makes a great deal of sense. Yes, he is a former minister of Agriculture, Forestry and Fisheries, making him a logical candidate on an intellectual level. However, as the representative of Nagasaki District #3, the second smallest district by population in the country, Yamada is set to lose his official position. For no matter under which reform of the House of Representatives one chooses (Each party has at least one reform plan. The Democratic Party of Japan has two. The New Komeito, terrified of being relegated to the ranks of a micro-party, has three.) Nagasaki District #3 is set to disappear.
Challenging the central leadership of the party has no downside for Yamada, as it might for others. Yamada has literally nothing to lose.