Bill Clinton endorsed Al Gore 44 days before the Iowa caucus. Why hasn't Obama endorsed Hillary?

Why hasn’t Barack Obama endorsed his former Secretary of State? 

There’s precedent. Bill Clinton endorsed and was giving speeches for Gore by this point in the 2000 election.

There’s no doubt that Clinton would want the endorsement. She already has a former President campaigning for her. She’s already running on extending the Obama legacy. Her last debate performance was focused on portraying herself as a better ally to Obama. So the lack of an Obama endorsement is a real slap in the face to someone who served in the top appointed position of his administration.

Instead, Obama just gave an interview with positive remarks about both Sanders and Clinton.

GLENN THRUSH: I mean, when you watch this, what do you — do you see any elements of what you were able to accomplish in what Sanders is doing?

PRESIDENT OBAMA: Well, there's no doubt that Bernie has tapped into a running thread in Democratic politics that says: Why are we still constrained by the terms of the debate that were set by Ronald Reagan 30 years ago? You know, why is it that we should be scared to challenge conventional wisdom and talk bluntly about inequality and, you know, be full-throated in our progressivism? And, you know, that has an appeal and I understand that.

Perhaps he feels his legacy is best furthered with another transformational President who gives full-throated support to progressivism. 

Obama may simply feel that Democratic primary voters should make their own choice without him weighing in. He may believe she’ll face a tough time getting elected as she faces investigations about her handling of classified documents and pay-to-play schemes with the Clinton foundation. Unlike the Benghazi obsession, these are scandals that may involve real criminal violations. There are limits to how often she’ll be able dismiss criminal charges by blaming the vast right wing conspiracy.

Or, Obama may have reservations about her performance as Secretary of State, such as her pattern of recommending more aggressive military action than Obama was willing to take. He may be concerned about handing the White House to someone who won’t be as reserved in the use of military power.

We can only guess why, but the failure to endorse is a real insult to Clinton’s campaign when she’s desperately trying to present herself as an Obama third term.