The existence of the 2A makes socialism impossible because only an unarmed populace can be subjugated. Put a different way, at some point the socialists will spend enough of other people's money to make further redistribution an impractical proposition without first removing the citizen's ability to say "enough is enough".
That would be repudiation of their core democratic position and put truth to subjugation of the populace
I guess the real answer to my question would be it was when they thought they held the majority or could persuade the majority. Seems we have passed that point in their opinion. I pray it is not the case.