@Kolyo,
I don't think the issue of who to blame for the current political situayion of the Democrat Pary is either particularly important or interesting. The observable fact is that there was a high degree of unanimity evident among the leading Democrats throughout the Obama years , and in terms of the legacy effects of the policies they followed, all share in the blame or credit one may wish to apply. Moreover that unanimity appears to be continuing. It may be that, with Trump in office, the various elements of the Democrrat party are adequately united only by a common enemy. If so, that should be sdufficient for a while, but possibly dangerous for then over time.
I think the truly interesting question and issue here is just what poliical factors caused the widespread defeats of Democrat cvandidates in the Presidential race; the Federal House and Senate, and in races for State legislatures and Governorships across the country? It does not appear that Democrats have yet come to grips with these questions and the underlying issues, which may influence elections in the coming years. It appears the last power blocs left standing among Democrats are those on the party's far left - at least that is what is suggested by the recent positions taken by Democrat leaders in both the House of Representatives and the Senate, and as well in the ongoing contest fort leadership in the DNC. Amidst all the ongoing anti Trump turmoil these issues may go unbresolved, leaving the Democrat political bench bereft of centrists and potential future leaders.
That's fine with me, but it may not be in keeping with their political interests.