Most people don't understand why Clinton is being talked about as if she is the defacto Democrat nominee.
The answer is quite simple: The media does NOT want to create a situation where democrats are actually competing against each other and have to discuss actual policies. They want to reserve this for the GOP primary.
In short, they want to create a universal acceptance of Hillary as the nominee. As such, they will most probably go HARD on any Democrat that tries to "go rogue" and run for president him or herself. They do NOT WANT to see a primary where actual ideas and policies have to be discussed, because they KNOW they can't come up with a coherent economic policy that doesn't involve its total subjugation by the edicts of Washington, as well as diplomatic policy that doesn't involve the plausible strong defense measures that is mandated by backing a functioning military, let alone a strong one.
What the media WANTS to do is to have the GOP play circular firing squad again, always making sure the conservatives are in the center of the circle, and by promoting the most mushy RINO as the "one who can help the Republican Party win the presidency!!" again. Of course, once the general election cycle restarts, the gloves come off.
But for this to be successful, the media must do what they can to preclude a Democrat primary debate. This is actually more important, especially as Obamacare falls flat on its face, and if the "Illegal Aliean legalizaton bill" happens, then this will allow them to run out the clock while they figure how to accompany all the illegal votes that will be harder to track because of said legalization.
Bottom line: the media will go all-out to help the Democrat Party avoid a primary to avoid answering tough questions as Obama is successfully doing now. Count on it.