CNN has fallen to fourth place among the cable news networks during prime time. This means that not only are they trailing Fox and MSNBC, but they are have even fallen behind their own HLN network.
CNN claims to fill the niche of actual news compared to the ideologically driven shows of Fox and MSNBC. Their problem is that they do the poorest job in the niche they have selected. If you want shows which promotes the fantasy-world imagined by right wingers, Fox does an excellent job of this. MSNBC, which had been in last place for years, has improved its line up of liberal opinion shows in recent months. CNN has a combination of opinion shows of their own which are lagging behind the other networks, along with shows which attempt to present more objective news. A right winger such as Lou Dobbs is at a disadvantage on CNN when most of the right wingers who are into cable news have their televisions permanently set on Fox. Their actual news shows are pretty weak at presenting the news, as I noted in this recent post. There may or may not be a potential audience in this country for a real news network. If there is, CNN does not satisfy that demand.
As for HLN, I watch it even less than the other three so I have no idea as to why even this is beating CNN.