There have been signs of crumbling support all across the country, with pensioners, soldiers, city councils and even former partners in the government coalition all throwing in their two dinars' worth.
But even if Mr Milosevic does go, what then?
Unlike Romania during the overthrow of Nicolae Ceausescu in December 1989, the problem is not a lack of opposition leaders. Rather, the opposite. There is a long list of people who are eager to see themselves as the next president. But the longer the list, the more comfortably Mr Milosevic can sleep. He has sat it out before, while opposition figures tear each other to pieces; he could easily do so again.
The best known of the opposition leaders is Vuk Draskovic, a bearded writer who in winter 1996-97 was one of the three main leaders of the unfortunately named Zajedno ("Together") coalition which spear- headed mass demonstrations against Mr Milosevic. The three leaders of Zajedno - Mr Draskovic, Zoran Djindjic of the Democratic Party and Vesna Pesic of the Civic Alliance - all used to behave on the podium as though they were best buddies. In reality, Mr Djindjic and Mr Draskovic barely spoke to one another, even while the "Together" demonstrations were at their height. Afterwards, the rift was unconcealed.
The charismatic Mr Draskovic has unbounded confidence in his ability to solve all problems, and contempt for anybody who does not share his views. He is universally referred to only by his first name, which means Wolf. At the rallies of winter 1996, the name of Vuk was enthusiastically chanted - as it was again on his maiden reappearance as an opposition leader in Kragujevac last night. He is generally assumed to be more interested in power than in policy - which, as far as many voters are concerned, is more of a plus than a minus point.
After the break-up of the Zajedno coalition, Mr Draskovic allowed himself to be wooed by Mr Milosevic, the man who had put him in jail only a few years earlier. Some in the opposition have not forgiven him. Mr Draskovic became deputy prime minister - before being sacked during the Nato bombing for demanding greater honesty from the Belgrade government. Even after the sacking, Mr Draskovic continued to be cautious about calls for Mr Milosevic's resignation, arguing that the Yugoslav president is the "legally elected leader". Not until last week did he suddenly change tactics - apparently worried that the revolution might happen without him - and demand that Mr Milosevic should go.
Even now, however, he is not ready to join hands with Mr Djindjic once more. The determination to schedule two rallies against each other - Mr Djindjic held one in Kragujevac on Thursday, only 48 hours before the Draskovic circus rode into town yesterday - served as a reminder that this was from now on to be the Apart coalition.
Mr Draskovic is convinced that he will remain more popular than Mr Djindjic. Certainly, the nattily dressed leader of the Democratic Party has a credibility problem among ordinary Serbs. Mr Djindjic gained a doctorate in Germany, and often uses the vocabulary of a sociological seminar - which does him precious little good at home. He talks of the need for democratic media and for social change. But he, too, has changed his views. During the Bosnian war, he dem-onstratively visited the Bosnian Serb capital, Pale, to show solidarity with Radovan Karadzic, the Bosnian Serb leader and indicted war criminal.
The incident serves as a reminder that political principles are in short supply in this region. His biggest selling point is probably that he can talk the language of the West, implying that he might be able to open economic doors if he came to power.
A clutch of other opposition leaders have a smattering of support across Serbia. Vuk Obradovic, a former Yugoslav army general who resigned at the beginning of the Balkan wars, is now the leader of the Social Democrats. His support is limited. But his military background could imply the stability that many Serbs hanker after. He is an old-fashioned Yugoslav, in that he has not succumbed to the nationalism that has overtaken others at different times.
Meanwhile, millionaire Serb-American businessman Milan Panic - briefly Yugoslav prime minister before being cast into the outer darkness by Mr Milosevic for showing a mind of his own - is sniffing around the possibility of a triumphant return. Like Mr Djindjic, but more so, his strongest card would be the perception that he could bring Western money back into a bankrupt Serbia. He has boundless enthusiasm which, even if misguided, can be engagingly infectious.
In many ways, the darkest horse of all is Vojislav Seselj, the pudgy leader of the far-right Serb Radical Party. Mr Seselj, who boasts a history doctorate, is no fool. He wears his xenophobia on his sleeve - often to advantage. His White Eagle paramilitary forces were especially notorious in the war in Croatia.
After the elections of 1997, his party joined a coalition with Mr Milosevic's ruling Socialists - it suited Mr Milosevic to have him inside rather than outside the tent. Now, however, he has distanced himself once more. Serbian official media try to present what has happened in Kosovo as a victory; Mr Seselj more plausibly depicts it as a defeat. He can thus portray himself as the man who would lead Serbia out of its darkness and back into the light.
If you ask Serbs which politician they support in place of Mr Milosevic, they tend to respond with a weary shrug. None-of-the-above is the most popular politician in the country. But it is remarkable how many people - embittered by everything that has gone so wrong in the past weeks, months and years - are ready to give favourable consideration to Mr Seselj.
If any opponents of the Nato bombing need the ultimate proof that their criticism was justified, this could be it. To move from President Milosevic to President Seselj would almost certainly create even greater problems than Serbia already faces. But Serbs do not necessarily see it that way; Mr Seselj is tough and proud. It is difficult to imagine Western leaders feeling nostalgic for the era of Mr Milosevic. But it just might come to that.
Vuk Draskovic, the best known opposition leader, is known above all for his changing views. He is currently opposed to Slobodan Milosevic, whose government he served in until recently. He is firmly convinced of his God-given right to lead.
Vojislav Seselj, leader of the far-right Serb Radical Party, was Draskovic's best man - then became his worst enemy. He is currently half-in and half- out of the gov- ernment. He is not technically part of the opposition. But if he decides to turn against Milosevic, his blows could be deadly.
Zoran Djindjic is leader of the opposition Democratic Party. He studied in Germany, and has the reputation of being most intellectual of all the opposition leaders. In the winter of 1996-97, he and Draskovic were officially close. They were two of the leaders of the Zajedno ("Together") coalition. The name could hardly have been more misleading. Both men did their best to elbow the other out of the picture.
Vuk Obradovic is a former army general who resigned at the beginning of the Yugoslav wars. Despite, or because of, his military background, he is the only one of the four who has never supported Serb nationalist forces. He does not currently enjoy mass support. But he is trusted more than Djindjic and Draskovic, both of whom are seen - not without reason - as slippery.