Emotional Intelligence consists on your ability to interact and understand others as well as your capacity to problem solve and diffuse negative situations or conflicts. While there is adequate training given to Homeland Security workers, emotional intelligence is actually a skill that is either innate, or learned and practiced with consistency.
It is quite possible that a disgruntled employee, or one which is prone to rash judgements, labeling, or is unable to analyze people and situations, will certainly pose a threat to the security of our country. After all, we have seen first hand what happens when assumptions are made about other people based only on their racial profiling.
Hence, suppose that a HS worker is met by someone who appears suspicious. If this worker does not remove his prejudices and assumptions from the situation, he is likely to be rude, sarcastic, or boisterous. This can certainly affect our safety because, whether he is faced by a terrorist or not, the image of dignity and respect of the agency would become jaded; that is a very bad thing considering that Homeland Security is like our immediate immune system.