Originally Posted by The Joker
I never felt Blake proved himself beyond all reasonable doubt that he was worthy of the mantle either. Batman had like three brief scenes with him in the whole movie, and not one of them showed he was the right guy for the mantle. At least with Dent he made him prove himself by seeing if he could get all those mob guys locked up first.
All Blake did was get his ass saved by Batman and tell him he recognized him from a look he used himself.
Dent had been showing a lot of things in the months before TDK, and even then, Batman asks Gordon if they can trust in him.