Are They Liberal Enough?

What worries me about this story in the Washington Post telling of a new liberal PAC seeking candidates to run against Democrats is its drive toward some kind of agenda coherence. That seems problematic to me. Don't the the conservatives and Republicans now have some serious problems not only because of the abject failure of all their policies but also because of their ideological conformity and rigidity? The new PAC might claim to be only interested in Democrats who aren't meeting their constituents' demands, but, I don't know, I somehow don't trust that. Besides, I thought constituents themselves decided that kind of thing in, like, elections. I know, I'm so naive.