I wonder if Trump has been playing dead hoping that she would do exactly that? You’ve got the Sanders people being egged on (or at least that’s how it looks to me) and Brexit is a good indicator that Clinton will have to go with Sanders, Warren, or someone like them. There’s no downside to playing to the left if Trump is polling horribly...
The thing is, once the veep is picked, there is no going back.
Trump might be crazy like a fox :)
My best guess is, Trump being as fast learner as he is, knows very well voter memories are notoriously short. Election is more than 4 months away. He does not want to peak too early by spending lot of money prematurely.
Reality is 40-45% of voters are lefties and will vote
Hilda even if she picks convicted congressman Chaka Fatah for running mate.
35-40% of voters will pull for Trump no matter what.
So it boils down to the remaining 20%, especially in battle ground 10 states.
Let us hope Trump has a October surprise in the bag and
is keeping powder dry for that.