Russian history seems to be the consolidation and ever so often breakdown of power due to, among other things, its geographical/geopolitical position and vastness. What I mean is, Tsardom arose out the threat of invaders from both the west and east and its Mongolian tutelage, as a large domain that demanded centralization. But even after the Revolution "tsarism" in Bolshevik dress seemed to be revived through Stalin's dictatorship, although for more complex reasons. How different were the power dynamics of Stalinism and tsarism? Was Stalin essentially a modernized tsar?
In other words did the Bolshevik Revolution change the fundamental power structure of Russian politics, or did it just make tsarism more dynamic in a modern world?
An extra question: did Stalin's death undo this regression towards tsarism?
Tsarism relied on an Autocratic leader who gained power via hereditary means and ruled with the aid of his 'advisors' who generally were either friends or family. Tsarism, for the large percentage, was ruled by one person and one person only, the Tsar, who could create and dismiss laws at his own whim. The Revolution of 1905 bought about a Duma which was a parliament of elected officials but this was essentially pointless as it could be disbanded at any moment and the Tsar had ultimate veto over everything, something which the Tsar did often. This can be summed up with that the Tsar ran the country and ruled it by himself with a small council of advisors who he often ignored (see the 1917 February Revolution in which they begged him to return from the front line to defuse growing discontent in the capital which he blissfully ignored).
The Bolshevik created Soviets which played on from the peasant councils of Tsarist Russia. However, they gave them more authority and could elect a representative. They did change the politic structure of Russian politics, they made it more 'democratic' which is a bad word to use but it allowed for more debate on the course of the country. The Bolsheviks, however, fell into the trap of allowing a 'cult of personality/individual' which Stalin expertly played. Stalin's rise to power was fundamentally different to that of a Tsar. Stalin had to use his own wit and use people (Zinoviev and Kamenev) to gain power instead of being born into it. He created a different version of Leninism and established himself as only below Lenin. He did create something akin to Tsardom but at the most basic level, he could be removed from below (all be it difficulty). Stalinism created a dictatorship, one with a head which could be cut off and was guided from below whereas with Tsarism the Tsar led by divine right instead of having to appease a party.