Thomas likes to talk about himself a great deal. it is often quite hard to move the topic of conversation away from his interests, achievements, and activities. the barrier to effective communication with tom is:

Self-preoccupation

Explanation:

Under this particular scenario, we can state that here the  barrier to compelling and persuasive communication with  individual is self-preoccupation. Self-preoccupation is referred to as or known as the state of being absorbed or engaged with the self or oneself. Here, it is given that Thomas tends to mostly talk about himself.

i believe that the answer to the question provided above is that the role of campaign committees is to act as a bridge between state and local campaigns.