Young people are particularly susceptible.
In fact, the goal of NLP (which is usually used in a clinical setting for constructive reasons) is to circumvent a person conscious, critical mind by lulling them into a kind of trance using repetitive phrases ("Yes we can"), repetitive movements (like Obama's metronomic switching of his head at a fixed tempo between his two teleprompters), pacing (the vocalization of common goals), and tonal shifts in speaking that create a tempo--all of which is designed to cause the listeners to begin to move as a group.
When the audience begins to move as a group and to respond and receive input as a group, its members begin to subordinate their individual critical thinking to that of such group.
Once entranced and behaving as a non-critical group, the speaker (Obama in this case) plants "post-hypnotic suggestions" (remember the line "when you are in the voting booth, you will have an epiphany. A beam of light will shine through a window and you will think, I must vote for Barack"). All the posters of Obama staring off into the future are also "suggestions" of a sort in that they are encouraging his followers to "deify" him (that is to place in him their sacred hopes.
In fact, if you look back at this campaign, you see an endless parade of group think inducement and post-hypnotic suggestions.
NLP — Tony Robbins? I’ve used his techniques. [So does the military.] They are powerful.