Is it 'rolling over' so much as it is realizing none of the other Democratic candidates would make anyone feel confident about securing the Presidency for at least another four years? Warren, O'Malley, Cuomo even... none of these people are Presidential material. I'm sorry.
Honestly, had it not been for Obama deciding to run, Hillary would be President right now. Depending on what went down in IL with Obama being a prominent Senator there, he may or may not have been able to hold on to his credibility enough to run in 2016.
Not to mention, had Hillary not employed Mark Penn early on I think she may have very well went on to beat Obama anyway. Also, 'rolling over' for the first black President to be succeeded by the first female President should make any Democrat proud and not feel like a tool. The guys on the right act like tools.
And the clown car of GOP candidates are Presidential material? Obviously no Democrat right now is as electable as Hillary Clinton, but I would still give the edge to any of the talked about Democratic candidates over whoever the GOP primaries spit out.
Also, while I would guess Clinton has a 80+% chance of winning the primary even if she faced a serious challenger, my concern is that without any competitive candidate in the primaries for the liberal Democratic voters to rally behind in the primary, Hillary can just coast through and run a center-right campaign in the general to go for an electoral blowout. I want Clinton to have to move to the left, and if she doesn't have to fight for the nomination at all, then she has absolutely no incentive to do so.