Let's see....Fox goes more liberal and looses what made it unique, looses shares. Just one more of the in-crowd but, hey at least they will begin to get accepted by the rest of the crowd.
not sure why they would shift, but they have likely hired some new producers and executives who want to make it "mainstream". So now they compete for the same demographic as CNN et al, and that audience is fixed, so they have no edge, no pool of people who they attract as viewers to them alone. Who wants to see Seymour Hersch get another 20 minutes on FNC? Or Tim Russert (who now seems to be Hannity's best friend).