Alexander II WI’s have come up a few times here, and others have tempered the ostensible benefits of his survival by suggesting that an 1881 Duma would not really be much more sovereign than 1905 Duma i.e. the tsar would retain significant veto power (which, unlike the UK monarch, is likely to be exercised much more actively) amongst other things. Apparently Alexander, while relatively enlightened, was still something of a ‘true believer’ in autocracy. This is the man who forcibly deported hundreds of thousands of Circassians for ethnic cleansing purposes, so it is hard to picture him as willingly taking a back seat to democracy. What will he do when something inevitably goes against his wishes in the Duma: will he be smart enough to turn the other cheek, or will his first instinct after a lifetime of being ‘unshakable autocrat’ be to just prorogue it in the manner Charles I? Much will depend on Alexander’s personality and political aptitude.
Another issue is that intangible factor of ‘political culture’. Aside from the obvious heavy currents of authoritarianism present at this time, the only other experience the country has had with mass, organised political institutions has been with populist socialists. Russia in 1881 has no real liberal tradition to speak of, and to say that by the 1890s a moderate party akin to the British Liberals or Conservatives could be in power seems optimistic. It should be noted that even today, partiality to autocratic government, along with deep suspicion and contempt for western institutions like democracy are prevalent in Russia. Almost a quarter century after the fall of the Soviet Union, Russia has yet to create a true, stable & efficacious democracy in large part due to a political culture whose last experiment with democracy before 1905 was during the day of Kievan Rus.
A Duma might prove, as in OTL, to be illegitimate and largely ignored, with the centre of politics being constituted elsewhere. Or it might become swamped with socialists intent on radical reform, causing the tsar to turn against it. There are just too many variables to predict with certainty what will happen. However, I agree that this is probably Russia’s last best chance to set up some kind of parliamentary system before a revolution breaks out. But it will be precarious and there is no guarantee of easy success. The key question will be whether or not, and to what extent, a diverse cross section of the Russian population will engage constructively with this institution.