President Pervez Musharraf's immediate threat may no longer be militants, or nuclear rival India, or an American Congress that is increasingly skeptical of the general's rate of return when it comes to the US-led war on terrorism.

This week, it is the ordinary citizens laying siege to his regime that could be more potent than any other threat, analysts say.

In an unexpected show of force, hundreds of lawyers and opposition politicians clashed with police on Friday and Saturday in Islamabad and Lahore, protesting the removal of Chief Justice Iftikhar Muhammed Chaudhry. Some of Musharraf's own party members have turned on him, and more protests are on the way.

Few say that they expect this to prove the undoing of the Musharraf regime. But the rattled opposition, long dismissed as ineffective or dead, has a new rallying cry. In championing constitutional rule, their united stance is quickly winning public opinion to their favor, considerably weakening Musharraf's reelection bid, observers say.

"If anybody thinks maintaining a dictatorship is easy – this is not Burma or Egypt. People will stand up," says Shafqat Mahmood, an independent political analyst in Lahore.

More than 100 protesters arrested

For almost a full week, Pakistan's major cities have seen a surge of violent protests against Musharraf's regime, pitting lawyers and intellectuals in bloody confrontation with the police. The spontaneous political reaction surprised many Pakistanis; given how carefully Musharraf's regime divided political parties over the years, many in the country's political establishment had written off the opposition's ability to push back against the president.

After years of building or burning bridges of political convenience, and working loopholes in the Constitution, the president has left the opposition and most political institutions stymied by apathy, internal conflict, or both.

"This is the cleverness of Musharraf's regime, the use of intelligence agencies and state institutions to scatter the political parties so there is no unity," says Mustak Ali Khan, a member of the provincial council of Jemaat-Islami, one of Pakistan's largest opposition Islamist parties.

The protests, now a week old, come at a critical juncture, observers say, and could snowball into an even larger movement. At their core is a new middle class which, with greater access to electronic media and more wealth, could prove instrumental in inspiring others to join the fray.

"They're the ones who have sacrificed their lives for democracy in the past. And I think they're ready to take bullets again," says Rasul Bahksh Rais, a professor of political science at the Lahore University of Management Sciences.

So far, as many as 100 people have been arrested. On Saturday, police injured 55 lawyers during a violent protest in Lahore. But the more the Musharraf regime cracks down, the more it appears to fan the fires of resentment and depletes whatever shreds of goodwill remain, according to observers.

But leaving the protests alone could prove more damaging for Musharraf. After seven years of military rule, Musharraf has a lot of enemies that could come out of the woodwork.

The man who took Musharraf to task

Attacking the judiciary appears to have been a serious miscalculation. Although weakened, it is considered the most sacred institution in Pakistan.

Chief Justice Chaudhry has proved to be an outspoken member of an institution known for its acquiescence. His abrupt checks on government power – including chastising the regime for failing to trace disappeared terrorism suspects – suggested that he alone might, if so inclined, rebuke Musharraf's bid to run for reelection in uniform, observers say.

His removal last week, on charges of misconduct that have so far not been made public, seemed designed to pave the remaining way for Musharraf's reelection, critics say, which the constitution technically prevents. Chaudhry's hearing before a Supreme Court panel began on Friday. He denies the charges.

The government dismisses allegations of foul play, saying that Chaudhry was legally removed according to constitutional provisions, since charges of misconduct have been building against him for months.

It remains unclear how these convulsions will affect the elections scheduled for later this year, although the government insists it will have no impact. Some believe that, greatly embarrassed by this episode, Musharraf will face even more dismal support at the polls. Many also fear that, given his eroding political support, Musharraf will attempt aggressive measures to hold onto power, including postponing elections or declaring a state of emergency.

"It's a new kind of tension of two imperatives," says Mr. Mahmood, adding that the unprecedented display of opposition may invite unprecedented forms of backlash from the regime. The only way out for Musharraf, some say, is to apologize and reinstate Chaudhry – though such a move, they add, is highly unlikely.