The greatest hour of the Social democrats was when they kicked out the Bolsheviks from the party in 1917 as reaction to the Bolshevik Revolution in Russia. This made Social democrats a reform party that accepted the already existing parliamentary system and the monarchy ("den borgerliga demokratin"). And by doing so the Social democrats paved the road to becoming one of the most successful political parties in the West.

By marginalizing the Bolsheviks it is likely that this saved Sweden from a bloody civil war, a civil war that our dear neighbors in Finland suffered from. Our modern history could have been very different, Swedes fighting other Swedes in bloody battles, an open wound that could have been present to this day. For saving Sweden and Swedes from this horror, I’m ever grateful.

That is why I rank Hjalmar Branting as the greatest leader of Social democrats, greater than both Hansson and Erlander.

I am of course fully aware about these affairs you mention, what I’m arguing is that Bolsheviks was accepted back into the movement in 70s.

There were many signs of this, not only in the policies that was enacted but also things like the open flirtation with communist dictatorships and letting well known communists back into the movement.