What I think is going on in Texas right now...

Obama had a big lead on the basis of the early vote - almost 150K votes. Now, with 14% or so of the precincts reporting (in addition to all the early vote), she has closed the gap substantially, to about 30K. BUT - it's mostly rural and suburban counties. Nothing yet from Travis (Austin). Nothing from Harris (Houston). Only 5% from Dallas.

It's only one scenario of what could be going on, but if it's the right one, we might see her continue to close that gap - even take the lead - but it should swing the other way once the urban precincts start coming in. If you remember what happened with MO on Super Duper Tuesday, when it took St. Louis a while to get its act together, this is the same phenomenon, but plus the early vote, which, again, Barack won big. So instead of a big Clinton lead disappearing at the end, like in MO, it's a big Barack lead switching to a dead heat, and, according to my guess about what's happening, widening again a little later in the evening.

On the other hand, the exits seem to say that she won among late-deciders, so if there's enough of them, that could swamp the early vote. But election day voters really would have to go big for Hillary for that to work.