I include Tamamoto-san on a tentative basis. Having met him on several occasions, I have a personal liking for him. He has gone through hell because of the machinations of his nemesis Komori. However, I have not read anything recent work by him published in Japanese. If the suggestor could send me a URL, I would be much obliged.
Some persons suggested Ozawa Ichirō and Ishiba Shigeru. While Ozawa and Ishiba and others politicians like Yosano Kaoru do write significant thought pieces and participate in taidan (discussion) works, their influence grows out of their positions in the political firmament, not necessarily the power of their ideas. Ishihara Shintarō and Inose Naoki, by contrast, established themselves as literary figures before becoming political players.