ASIA : Japanese Premier Stumbles on Rocky Political Landscape : Hosokawa’s public support is down 37% on eve of summit with Clinton. Even a rebound in the polls might not bring him the authority he needs.

He is the “war criminal of the 7% tax,” one magazine blared. An “alien prime minister” masquerading as Mr. Clean who actually gives and takes sweetheart deals to favored firms, trumpeted another.

He uses “Hitler-like tactics” and back-room bargaining despite pledges to usher in a new era of open government. And, in one poll, his public support had plunged a whopping 37% in the last week.

Can this be Morihiro Hosokawa, Japan’s fresh-faced prime minister who was supposed to be an agent of change and voice for reform? Is this the man blessed with public approval ratings in the 70% range despite taking controversial action to open Japan’s rice market, squarely apologize for the nation’s wartime misdeeds and tackle political reform?

As Hosokawa meets President Clinton today, it is clear his public standing has, at least temporarily, taken a steep dive. This month’s political snafu, in which he abruptly announced a new 7% tax increase, then was forced to renounce it by the ensuing public uproar, shook public trust and prompted a stream of unflattering headlines.

“The honeymoon between Mr. Hosokawa and the public is ending,” said Seizaburo Sato, a Tokyo University professor emeritus affiliated with a think tank established by former Prime Minister Yasuhiro Nakasone of the Liberal Democratic Party.

“Most Americans have too rosy a picture of his abilities. He looks young and fresh. But he is not so talented or smart. He lacks experience. And his political base is weak, so he’s an easy target to be manipulated by the bureaucrats.”

Not that the redoubtable Hosokawa can’t spring back. His support ratings, ranging from 52% to 59%, may be his lowest. But that is still considerably higher than past prime ministers enjoyed: The popular Toshiki Kaifu drew an average 48%; Noboru Takeshita’s plunged to 3% just before his resignation in the money-for-stocks Recruit scandal.

With his telegenic appeal and aristocratic elegance, Hosokawa has somehow weathered not only policy snafus, but also negative coverage of his “women problem” and alleged sweetheart deals with the giant Seibu group and the gangster-linked Sagawa Kyubin transport firm.

“His administration has proven more resilient than most people anticipated,” said Kuniko Inoguchi, a political science professor at Tokyo’s Sophia University. “People forgive him because he’s young, inexperienced and because they think he’s trying to do something new in a very traditional setting.”

In any case, she said, “Clinton has no alternative to Hosokawa.”

But how effectively Hosokawa can manage his end of the U.S.-Japan relationship may ultimately have little to do with his public standing at home.

For the United States, the more important questions are:

Do Hosokawa’s decisions carry final authority? Not necessarily, as his tax fiasco starkly illustrated.

Whatever summit agreements may or may not be reached today, does Hosokawa have the power to force the mighty bureaucracy to implement them as the United States expects? Almost certainly not.

Although Hosokawa pledged to curtail the power of the bureaucrats when he became prime minister last August, in fact, say many analysts, they have become stronger because the inexperienced coalition government has had to rely more on their expertise. So far, bureaucrats have resisted other Hosokawa pledges, such as far-ranging deregulation.

And is Hosokawa--or his seven-party coalition--likely to be in power beyond the year? Perhaps not. As Yomiuri newspaper political editor Shoichi Oikawa put it: “The critical point is not whether the (tax) affair will undermine his popularity. What matters most is that it has caused a deep crack in his political power base.”

Many analysts here see an inevitable split in the coalition between the forces of Ichiro Ozawa, the Japan Renewal Party official who wants Japan to take a more aggressive international role, and those of Masayoshi Takemura, the New Party Harbinger leader who urges a more circumspect role for Japan as a “small but shining nation.”

For the United States, that will make the political landscape even more difficult to fathom.