Just four months after they descended from the hills as conquering heroes and declared themselves the new masters of Kosovo, the political leadership that emerged from the Kosovo Liberation Army is suffering a collapse of its support, according to voter surveys, interviews with ordinary ethnic Albanians and even senior figures in the rebel movement.

The former guerrillas are ensnared in a deep political crisis, caused by popular unhappiness with their heavy-handed power grabs, rising disgust about the violence plaguing Kosovo and the rebels' underestimation of their political rivals. The political party formed this week by Hashim Thaqi, the political leader of the former guerrilla force, would be crushed in provincial elections at all levels, according to Western and Albanian analysts here.

And if presidential elections were held today, Thaqi would be easily defeated by Ibrahim Rugova, the moderate ethnic Albanian political leader who led a 10-year, nonviolent resistance campaign against the Belgrade government. Only months ago, the KLA and some Western observers were dismissing Rugova as a politician of little influence who had been overtaken by events.

Rugova has the vote of Lumnie Musa, who comes from the village of Prekaz, the scene in February 1998 of the first major Serbian assault on a KLA stronghold, and home to the fallen national hero, Edem Jashari.

"He's more democratic, more civilized," said Musa, whose house was leveled by Serbian forces.

A scientific opinion poll that was commissioned by a Western organization and has not been released found 4-to-1 support for Rugova over Thaqi. A recent, unscientific survey of 2,500 voters by an independent media organization here found that Rugova would win 92 percent of the vote in a two-way race with Thaqi. And the rebels' support in former KLA strongholds, such as the Drenica area in central Kosovo, Thaqi's home base, has withered to single digits.

Even allowing for a large margin of error in the surveys, the results represent a stunning reversal of fortune for the rebels, who have quickly wasted much of the political capital they enjoyed after NATO troops entered Kosovo on June 12.

The first elections in Kosovo are still months away and will probably be held only at the municipal level, according to U.N. officials, who want to put off province-wide contests. But a senior Thaqi adviser said that the rebel leader realizes the scale of his political problems and now needs to initiate radical changes if his new political party -- the Party for the Democratic Progress of Kosovo -- is to have any chance of governing.

"Hashim lost a lot of friends in the war and made a lot of sacrifices," said an adviser. "He believes he is a better leader than Rugova, so it's very bitter and disappointing to know that Rugova would win."

Much to the former rebels' disbelief, Rugova has large residual support among ethnic Albanians. Interviews with potential voters found they seemed to compartmentalize the two major political elements, viewing Thaqi as a military man and Rugova as their natural leader.

"Rugova is a mysterious, mystical figure for people," said independent analyst Ylber Hysa, who noted that Rugova became a distant but revered figure partly because he was banned from Serbian television except when he was pilloried. An intellectual who can be indecisive and isn't known for his charisma, Rugova has never had his political weaknesses exposed, Hysa said.

Rugova's strategy of "doing nothing" is working for him, Hysa said. "People have had very little concrete contact with his politics. Their contact with the KLA, on the other hand, is through war and destruction."

After the war, the KLA generally abandoned rural areas and carried out a high-handed assumption of power in the cities that left many devastated families bitter.

On April 2, during the second week of NATO bombing, Thaqi formed the interim or Provisional Government of Kosovo , a KLA-dominated structure. And within days of NATO entering Kosovo in June, it established a series of national departments in Pristina, including ministries of Reconstruction, Interior and Finance. By late July, the provisional government had established local authorities, including "mayors" in major municipalities.

This power play, often crudely executed, has been a disaster for Thaqi, said one of his advisers and other independent observers. By declaring itself the only legitimate government of Kosovo, the KLA unrealistically raised expectations that it could get things done.

But real power, through its command of Western purse strings, lies with the United Nations. It is administering the territory under a Security Council resolution and does not recognize Thaqi's government.

Ethnic Albanians had unrealistic expectations of how quickly the country would be rebuilt, said U.N. officials. And with winter looming and hundreds of thousands of people facing the cold in temporary shelter, resentment has rebounded on Thaqi's government as well as the United Nations.

"They claimed to be some kind of government," said Hysa. "If you say you're the government, people expect you to govern."

The KLA also set up an Interior Ministry with shadowy policing powers, but Kosovo has been scarred by a wave of vicious violence against Serbs. Human rights groups and others believe members of the KLA -- now transformed into a lightly armed and uniformed civil emergency force called the Kosovo Protection Corps -- are involved. And many ethnic Albanians blame Thaqi, despite his public condemnations of the violence.

Some in Thaqi's circle now believe the interim government was an illusion that bestowed only the trappings of power -- fancy cars and bodyguards -- on the KLA leadership. And they believe Thaqi should concentrate on building a grass-roots political organization and jettison the fiction that he is head of a government. But that is a hard sell within the government.

"It's hard to tell the minister that maybe it's better if he's not minister anymore," said the Thaqi adviser. Thaqi is said to be dispirited and in a recent meeting with Western officials wisecracked that he wouldn't mind a job in Washington.

The former rebels' problems are even more pronounced at the local level. Young rebel soldiers, many with wads of German marks and late-model Audis, swept into towns and installed themselves in municipal buildings. They often excluded longtime and more moderate elements in the community from participating in reconstruction.

"Thaqi's people are more arrogant and aggressive, acting like they are the big bosses," said Bekim Mazreku, a shopowner in Malisevo. Mazreku said he respects what the rebels did during the war, but now he is disillusioned.

"The big jeeps and the fast cars are irritating people," said Xhafer Murtezaj, 51, an activist for Rugova's Democratic League of Kosovo in Srbica, also a onetime KLA stronghold. "They got the Serb flats, and the people who suffered a lot don't have anything."

In the southern town of Kacanik, for instance, an Albanian-American restaurant manager from Greenwich, Conn., who fought with the KLA has set himself up as "mayor" -- to the consternation of many locals.

Rugova's party has not challenged these kinds of power plays, but is instead registering new members and priming its parish-pump politics.

"They're going to weddings and funerals," said the Thaqi adviser. "That's what we should be doing."

Violence at the local level -- including the intimidation of political opponents, particularly members of Rugova's party, and threats against ethnic Albanian women who date international workers -- have also rippled through communities.

In August, at a meeting of all political parties in the eastern city of Vitina, a KLA commander warned that anyone who engaged in anti-KLA propaganda would be "punished." Thaqi's government, he said, would begin "registering" political parties that could participate in the political process, according to internal reports by the Organization for Security and Cooperation in Europe.

"Their arrogance is catching up with them," said one U.N. official.