I don't mean to be rude but you are calling something "obvious" which is far from obvious. There is considerable disagreement on whether the Bolsheviks had a majority before the withdrawal of the Mensheviks and non-Left SR's.
(1) The Wikipedia article
http://en.wikipedia.org/wiki/October_Revolution states that "The Second Congress of Soviets consisted of 670 elected delegates; 300 were Bolshevik and nearly a hundred were Left
Socialist-Revolutionaries, who also supported the overthrow of the
Alexander Kerensky Government." In a footnote, it gives as its source Robert Service's *A History of Twentieth Century Russia*
(2) Alexander Rabinowitch, *The Bolsheviks in Power: The First Year of Soviet Rule in Petrograd*, p. 29: "Bearing in mind that at the start of the Second Congress of Soviets the Bolsheviks did not have a majority without support from other 'internationalists'..."
https://books.google.com/books?id=BEoBCGJ4VqYC&pg=PA29
From the same book, p. 409:
" According to a preliminary report by the Credentials Committee, 300 of the 670 delegates to the congress were Bolsheviks, 193 were SRs (of whom more than half were Left SRs), 68 were Mensheviks, 16 were United Social-Democratic Internationalists, 14 were Menshevik Internationalists, and the remainder either were affiliated with one of a number of smaller political groups or did not belong to any formal organization. An overwhelming number of delegates, some 505 of them, were firmly committed to the transfer of “All Power to the Soviets,” that is, to the creation of a Soviet government that reflected the party composition of the congress (M. N. Pokrovskii and Ia. A. Iakovleva, eds., Vtoroi vserossiiskii s”ezd sovetov R. i S. D. [Moscow-Leningrad, 1928], pp. 144–153)."
https://books.google.com/books?id=ZmzWDwAAQBAJ&pg=PA409
(3) Even the Wikipedia article you rely on acknowledges a dispute about whether the Bolsheviks had a majority: "According to the bureau of all factions, by the opening of the congress 649 delegates were present of which: 390 were
Bolsheviks, 160
Social Revolutionaries, 72
Mensheviks, 14
United Internationalists, 6 Mensheviks-Internationalists, and 7 Ukrainian socialists. By the end of the congress, after the departure of the right-wing socialists and with the arrival of the new delegates, there were 625 delegates, of which 390 were Bolsheviks, 179 left-wing Socialist Revolutionaries, 35 United Internationalists and 21 Ukrainian socialists. Thus, the Bolshevik-Left Socialist Revolutionary coalition won about two thirds of the votes there.
According to other sources, 739 deputies arrived at the congress, including 338 Bolsheviks, 211 right and left Socialist Revolutionaries and 69 Mensheviks." [emphasis added--DT]
https://en.wikipedia.org/wiki/Second_All-Russian_Congress_of_Soviets_of_Workers'_and_Soldiers'_Deputies
(4) Vladimir Brovkin writes in *The Mensheviks After October*:
"As Oskar Anweiler has pointed out, the Bolsheviks, even at the height of their success, had a very narrow margin of numerical strength over their opponents. According to the Credentials Commission's figures, the combined strength of the 200 SR delegates and the 92 Menshevik delegates almost equaled the 300 Bolsheviks.
"The official breakdown of the political forces at the congress, however, did not correspond to the real alliances and antagonisms. The data from personal questionnaires give a somewhat more precise picture of the numbers in various factions. Of the 98 Mensheviks, according to this source, 62 were Martov's supporters, 14 backed the Menshevik Central Committee, and 22 belonged to the Defensists' faction. These groups had fundamentally different political objectives. The SRs, the second largest faction at the congress, were also split. The Right SRs sided with the Defensist Mensheviks; the Left SRs were Martov's partnetrs in the Left Bloc. The Bolsheviks, as is now well known, were divided as well, into radicals, led by Lenin and Lev Trotsky, and conciliatory Bolsheviks, led by Lev Kamenev and Grigorii Zinoviev. The political struggle at the congress developed on two planes: the leftist soviet parties — Bolsheviks, Menshevik Internationalists, and Left SRs — versus the rightist soviet parties — Right SRs and Defensist Mensheviks; and within the left wing itself, conciliatory Bolsheviks, Left SRs, and Menshevik Internationalists versus etremist Bolsheviks.'
https://books.google.com/books?id=cP0xLtu1aZgC&pg=PA17
(5) Stephen Kotkin in *Stalin: Volume 1: Paradoxes of Power, 1878-1928*, p. 217, writes: "Smolny's colonnaded hall...had filled up with between 650 and 700 delegates...Somewhat more than 300 were Bolsheviks (the largest bloc), along with nearly 100 Left SRs..."
So it is far from "obvious" that the Bolsheviks initially had a majority--especially if Rabinowitsch is correctly quoting a book on the Congress published in the USSR in 1928 and co-edited by Pokrovskii, who would not seem to have any motive to understate the strength of the Bolsheviks.
That the Bolsheviks and Left SR's
combined had a majority at the Congress is another matter, something I do not deny. My point. however, is that the Left SR's too favored a coalition government of all the parties represented in the soviet--as indeed did many Bolsheviks. As I put it in a post a couple of years ago:
"So there may or may not have been a slight Bolshevik majority. But there clearly was not a majority for Lenin and Trotsky's goal of an all-Bolshevik government. In fact, when Martov called for a coalition government, the Bolsheviks did not dare to oppose his resolution--it passed *unanimously.* But then the more right-wing of the Mensheviks and SRs insisted on walking out because the Bolsheviks had resorted to an insurrection without waiting for the Congress to act--and then Martov joined them.
" If the Bolsheviks had waited until the Congress had met, there would have been no need for an insurrection, and the moderate socialists would not have walked out. The demand of virtually all non-Bolsheviks (including Left SRs) and many Bolsheviks for a coalition government would have been extremely difficult to resist. As it was, the Bolsheviks could say the walkouts were "traitors" who deserved no role in the new government, which was basically a one-party Bolshevik government with some Left SR window dressing."
https://www.alternatehistory.com/forum/threads/wi-lenin-dies-circa-august-1917.342336/#post-10250410
Again, I am not denying that there was a left-wing majority in the congress. I am not denying that there was a majority for transferring power to the soviets. But that is not the same thing as a majority for a government completely dominated by the Bolsheviks. And yes, I am well aware of the problems a genuine coalition socialist government would face (perhaps I should have been more explicit about them in the post from 2001 that I reposted but even there I wrote "
At least for the time being, Russia would be on the road to peaceful political compromise rather than civil war." [emphasis added]) Yes, there would still be resistance from counterrevolutionaries but it would be even more feeble than it was in early 1918 in OTL. (Amusingly, Lenin in the spring of 1918 stated that the civil war was basically over! "In the main, however, the task of suppressing the resistance of the exploiters was fulfilled in the period from October 25, 1917, to (approximately) February 1918, or to the surrender of [Ataman] Bogayevsky."
http://www.marxists.org/archive/lenin/works/1918/mar/x03.htm)
