- Stuff Happens. If Hillary has a major health event, we do not want the party leadership coalescing around someone "safe", because there are Democrats to the right of Hillary, and that's pretty much the leadership's definition of "safe"
- Having Democratic debates in parallel to the Republican debates gives our candidate visibility
- Being challenged from the left makes Clinton look more "centrist" in the general - which, ironically, gives her room to edge left with the MSM / Village
- Giving progressive ideas visibility helps move that thrice-damned Overton Window back toward the center from the extreme right
- It gives the presumably more progressive candidate experience and visibility
- It helps HRC refine her arguments for the general
For these reasons, I think this site should use its influence to encourage "better" Democrats to make a probably-futile challenge to Hillary Clinton for the 2016 nomination.
The above is all assuming she wants to run. And if she doesn't, we need those better Democrats to be ready to mount a campaign tomorrow.