Elected nearly three years ago under Communism, the Congress had until yesterday focused its anger on President Boris Yeltsin and his reforms, chipping away at his authority and savaging his policies.
But with 1,033 members and 14 different factions, the Congress was never a focused forum of opposition. It has delivered lopsided majorities against Mr Yeltsin, forced him to dump his prime minister, Yegor Gaidar, and revelled in its role under the constitution as the 'supreme organ of state authority'.
Its success in undermining Mr Yeltsin, though, depended to a large extent on the skill and cunning of its chairman, Ruslan Khasbulatov, a former professor who first came to prominence by defying the 1991 coup. After the putsch, though, an alliance with Mr Yeltsin turned into bitter rivarly.
Backed by a powerful parliamentary bureaucracy, Mr Khasbulatov turned the Congress and a smaller standing parliament, the Supreme Soviet, into a battering ram against radical free-market reform. His power sprang from his ability to impose a fragile order on parliament's feuding factions, imperiously cutting off debate, ramming through votes and dispensing favours.
Yesterday, though, he lost control. Congress rebelled and tried to sack him. He survived, as did President Yeltsin, but he is badly wounded. Hugely unpopular with the public and handicapped by his non-Russian origins as a Chechen, he has no power base outside parliament. His struggle with Mr Yeltsin, though tinged with bitter personal antagonism, was always rooted in a a deeper struggle between the legislature and executive. This struggle will rage on. But Mr Yeltsin was last night claiming victory.
The revolt against Mr Khasbulatov followed his announcement yesterday morning of a proposed deal to end a power struggle that has paralysed Russian government for months and raised the spectre of violent confrontation.
The deal, like an early pact in December, was worked out in all-night negotiations between Mr Khasbulatov, Mr Yeltsin, and the head of the Constitutional Court, Valery Zorkin. It called for elections in November and the abolition of Congress in favour of a smaller bi-cameral legislature. Anticipating trouble, Mr Kashbulatov ended a brief statement with a diffident call for debate: 'Now if you wish, we can exchange opinions.'
The Great Kremlin Palace erupted. A parade of deputies stalked to the podium to denouce the deal as treachery. 'Yesterday you said that Russia was fed up with us. Well, maybe,' fumed Vladimir Isakov, a leader of the conservative Agrarian faction. 'Excuse me but we are fed up with you.'
Finally, after months of quarrels over arcane points of constitutional law, the real issue is out in the open: it is survival. Mr Khasbulatov violated the one thing all Mr Yeltsin's opponents could agree on - the need to preserve their own positions.
In rebelling so angrily, deputies may have delayed their own extinction but they have not halted it. Without Mr Khasbulatov's firm hand, Congress risks splitting into raucous disarray. Nearly 90 per cent of its members are former Communist Party members but there is little to hold them together beyond a general dislike of reform. During the past three Congresses, two of them emergency sessions, conservatives have mustered solid majorities of around 650 votes. Mr Yeltsin's supporters can count on only 240.
But the conservatives are divided. The largest bloc, Russian Unity, has four separate factions, embracing neo-fascists, nationalists and state farm managers with no real interest other than stopping land reform. Their anger at Mr Khasbulatov has been brewing since December, when he reached his earlier deal with Mr Yeltsin. He later rejected the pact as the 'work of the devil'. Whether he can recover from yesterday's ordeal though seems less likely. The rage he directed so successfuly against Mr Yeltsin has been turned on him.
'The Congress is not a monster out to destroy everything,' said Mr Zorkin, before the current session. Mr Yeltsin was not convinced. After yesterday, Mr Khasbulatov may have his doubts too.