Assuming that you want this simplified...
Use the FOIL method and combine like terms:
And your final answer is: 
It was so the delegates would be free to say what was on their minds. If anything about what they said would go to the public, there would be people who would be mad at them and thus possibly hurt them. It was to protect them.
Because when they are selfish and choose their career over the good of our own people this is A. Generally a huge character flaw and B. Because our country needs to be protected and safe, our elected officials are elected to represent us NOT to further their own advancement.
It would be like the government that is in the USA, it can't be a direct democracy as that would mean everyone votes on everything. Not only is it not efficient but also the general population often does not possess enough knowledge. That's why we have electoral college votes in USA because the people are not trusted.
