Agreed, and I believe his failure was more in leading his own party than keeping the Republicans in check. In the opening months of the Obama administration, Democrats were bouncing off the walls like kids at a serve yourself frozen yogurt store. The lack of prioritizarion, vision and leadership is what cost them the midterms, snd here we are.
The lack of prioritization, vision and leadership as you describe may be an apparent symptom of the party, but IMO, not the cause. I feel the cause of such symptoms have more to do with the typical Dem legislator's habit of being more individualistic, more reflective and, dare I say, more attached to the needs of their constituency, especially when compared with the Repub's legislators more like-minded and "orderly" approach toward accomplishing their national agenda?
If I recall, once upon a time before the severe in-fighting occurred when the Tea Party mounted their hostile takeover of the Party proper, the term lock-step was exclusively reserved for describing the GOP. As the Party's problems mounted with the ever tightening grip that the Tea Party exerted over it (remember how costly it was for the Party proper when the "insurrectionist Tea Party faction" forced a partial shutdown of gov't services?) Remember Boehner having to resign because he could not control the hardliner Tea Party caucus that wanted to burn everything to the ground so they could reshape the nation in their image?
Well, it seems to me the one single remnant of that internal struggle, and also the glue that's keeping the party from completely falling apart is the abject obstructionist policy the Repub Party came up with "to force Obama to be a one term president". Sure, that policy failed miserably in that it not only failed to keep Obama from being re-elected, but it also failed from totally obstructing Obama's many accomplishments during his two terms.
Yet, true to form, the Repubs are in lock-step in this regard.