Thats a great observation Craig just he said think of a card with no patter that i saw influencing him towards anything. I dont think he had him choose one earlier and thats what he was "thinking" either which is the way id accomplish it as of now. Thats how it was many times when he asked for a thought of card he also didnt have some type of setup in his pockets which i know exist after he asked for a thought of card becuase his hands were always in view its reallly something...
You didn't see anything or a force because it is a TV show, and TV shows are edited. You don't ever see the set-ups.
In terms of magic presentation, this is a good lesson for new magicians to learn. What you are describing is an illusion that is created by his patter and presentation. Look up the trick "Imagine" By G. This is a perfect example of how patter and presentation can be used to achieve what you saw Blaine do. Basically, you shape the audience's perception of what really happened.