One can only imagine what Stephen Colbert will have to say about this.
We've been down this road before with Reuters: see Arnold Zwicky's 2007 post "From the headline desk at Language Log Plaza" and my followup, "Reuters says guilty of elliptical headlines." As we've documented, it's long been the peculiar Reuters house style to create headlines of the form "X say(s) C," where C is a complement clause missing a subject. This time around, the elision of the pronoun it results in crash blossom-y goodness, since the casual reader would assume that the subject of "Bears Part Of Blame For Senate Loss" is actually bears, construed as a plural noun, with the rest of the clause serving as predicate (and with the copula are deleted in typical headline style).
This goes to show just how engrained the "X say(s) C" formula is at the Reuters copy desk, if they can rattle off a headline like this without stopping to consider how it would read to anyone not steeped in Reuters-ese.