Probably both--we will likely never know for certain.
The one thing we need to do is to stop squabbling after the primaries. Once the nominee has been announced, we are past the time for in-fighting and grudge-carrying.
Put forth your best candidate, and yes, fight like hell for that candidate--in the primaries. Once the primary is settled, push for the nominee. The failed candidates need to also kick into high gear, campaigning hard for the victor. (And that means endorsing the victor, unlike Ron Paul.)
We do ourselves zero good by pouting & staying home--the result is the ugly mess we're facing right now.