BELGRADE, Yugoslavia: Serbian university students filled the streets of Belgrade again protesting what they see as a stolen election, and calling on the United States for help. As they passed the U.S. Embassy, booing a detachment of heavily armed riot police, they chanted U.S.A., U.S.A., We want changes." After Serbian President Slobodan Milosevic had the courts dismiss municipal election results which would have brought the four-party opposition coalition Zajedno a majority on the Belgrade city council, demonstrations of angry students filled the streets, the number of protesters reaching 100,000 yesterday. As the students chanted slogans and pelted official buildings - state TV and a Socialist Party branch - with eggs, Milosevic's political opponents appealed to the Serbian Supreme court to overthrow the lower court ruling and restore the election results. So far, Milosevic has stubbornly resisted any concessions. continues to control the media and squelch any market reforms. Although he is at the root of the wars which tore apart the old Yugoslav federation in 1991 - 1992, he later helped end the conflicts, using his influence over Bosnian Serbs to push through the Dayton Peace agreement. The opposition has little chance of pushing Milosevic out of power, and no chance of continuing Serbia's role of influencing the Bosnian Serbs if it did. "Milosevic has a solid grip on the main levers of power," says TIME's Central Europe bureau chief Massimo Calabresi. "His police force numbers 80,000 men, who are well paid, and paid on time. The army, by comparison has to wait months for their paychecks, sometimes. The police are largely loyal to Milosevic, and are being rotated between cities now so demonstrators in Belgrade do not face Belgrade police. There is less chance for the cops to side with fellow citizens. There is the possibility of violence - 100,000 people, or even 30,000 could cause a lot of trouble - but it would probably just play into Milosevic's hands since he could crush the demonstrations citing concern for public order." Milosevic is likely to survive this challenge to his authority, but his continued rule will be complicated by Serbia's economic problems. "There is widespread pessimism over the economy," says Calabresi. "No one has any faith in Milosevic's ability to handle the situation. It's a mess, and people do not feel that it is becoming any better under Milosevic, given his tendency for central control."