In politics, the worst wounds are usually self-inflicted. Just ask Bill Clinton, Richard Nixon, George H.W. Bush, Howard Dean and — now — Ariel Sharon. The Israeli prime minister not only lost a critical vote on Sunday, May 2, but he also damaged his relationship with an American president who went far out on a limb to help him, only to have it sawed off.

Some may debate whether George W. Bush’s wounds from the resulting tumble were also self-inflicted; they may argue that he never should have climbed out there with Sharon. But in fact he had little choice.

Sharon boxed in the administration with his Gaza disengagement plan, leaving Washington little choice but to back him or appear to be opposed to dismantling Israeli settlements and turning territory over to the Palestinians. After weeks of negotiations, the administration was able to get enough improvements in Sharon’s proposal to endorse it.

Problem was, Sharon conducted virtually all of his negotiations with the Americans, to the exclusion of nearly everyone in his own government. About the only Cabinet member he appeared to take into his confidence was Ehud Olmert, the deputy premier and Sharon’s heir apparent.

Olmert had floated a more ambitious disengagement plan earlier in what may have been a tactic to make Sharon’s limited Gaza proposal more palatable, and he ran the referendum campaign.

The 60-40 vote against the plan on May 2 was a humiliating defeat for Sharon, and worse for Olmert’s ambitions.

Shared defeat is more likely to push Bush and Sharon apart than draw them closer together. The personal relationship, never the warm friendship the spin doctors portrayed, is facing intense strain at a time when neither man can afford it.

Whatever anger the Bush administration may feel, don’t look for it to show up in public before Nov. 2. The president has higher priorities.

After the big White House photo-op and letter swap last month, Sharon seemed to think he could coast to victory at home. If he’d been as vigorous in courting his own party as he was in convincing Bush, the outcome might have been different.

Sharon’s over-confident failure to mount the kind of campaign his foes did undercut Bush both politically and diplomatically. It made Bush’s backing seem worthless, and it incensed allies in Europe and the Arab world whose help he is courting to bail out his failing Iraq policy.

Jordan’s King Abdullah canceled his White House meeting to show his anger (he was scheduled to come back to Washington on Thursday, May 6, seeking his own letter of assurance), and Egyptian President Hosni Mubarak said America has never been so hated in the Arab world. Bush should have been able go to the Tuesday, May 4, meeting with his Quartet partners — the United Nations, the European Union and Russia — touting a potential break in the Israeli-Palestinian stalemate, but instead he was rebuffed by Likud voters.

Sharon got no help from the State Department, which immediately after the White House meeting began spreading the word that there was nothing really new in the Bush commitments to Sharon.

The administration sought to assure Arab and European leaders that nothing had changed, that everything was still up to the parties themselves to negotiate. But reality was not enough to overcome the perception of a dramatic shift in American policy — with one notable exception: Israeli opponents of the disengagement plan.

They ran a masterful campaign and were able, without getting personal, toportray two of the world’s leading anti-terror warriors, Bush and Sharon, as staging a “retreat” that amounted to a surrender to terrorism.

Opponents were able to motivate their supporters, while Sharon made little attempt to rally his, or to convert others to his cause.

Sharon blundered by going to the Likud ranks, where the opposition has been intense and the settlers wield real power, instead of directly to the general public, where polls consistently have shown 60 percent support, the opposite of the Likud tally.

Some on the left opposed Sharon’s plan because they fear he will evacuate Gaza and stop there; the right fears that leaving Gaza will be just the beginning of a broader disengagement.

No one really knows what he really has in mind: Gaza first or Gaza last.

There may be only 7,500 settlers in Gaza, but the message was clear for the nearly quarter of a million Israelis living in the West Bank that they could be next.

The Bush administration, which has all along called for removing settlements, touted the Sharon plan as the first concrete move by Israel to actually dismantle settlements, and thus a reason the Arabs and Europeans should encourage it. The May 2 referendum could prompt a U.S. backlash, with a renewed focus on settlements as obstacles to peace.

Sharon said he is reworking his plan in the hope of getting it through his Cabinet, which didn’t like the original, but can he do that without losing Bush’s backing? He may find out later this month when he plans to be here to speak to the American Israel Public Affairs Committee’s policy conference and hopes to meet with the president.

Bush invested considerable political capital in Sharon’s first plan and lost because the prime minister failed to sell it to his own party. That’s the kind of failure this administration, beset with diplomatic and political difficulties, can ill afford.

Douglas M. Bloomfield is a Washington, D.C.-based political consultant who was formerly chief legislative lobbyist for AIPAC.