What is the deep state? How does it operate? Why does it exist? What are it's political goals?

From Wikipedia:

Deep state in the United States

In the United States the term "deep state" is used within political science to describe influential decision making bodies within government that are relatively permanent and whose policies and long-term plans are unaffected by changing administrations. The term is often used in a critical sense vis-à-vis the general electorate to refer to the lack of influence popular democracy has on these institutions and the decisions they make.[1][2]

https://en.wikipedia.org/wiki/Deep_state_in_the_United_States

Mainstream media take on it:

The 'deep state' is real. But are its leaks against Trump justified?
Jack Goldsmith

Even the most severe critics of the US president should worry about this subtle form of anti-democratic abuse

https://www.theguardian.com/commentisfree/2018/apr/22/leaks-trump-deep-state-fbi-cia-michael-flynn

Other related:

https://en.wikipedia.org/wiki/Council_on_Foreign_Relations
https://en.wikipedia.org/wiki/Bilderberg_Group

Quote from Edward Bernays:

'The conscious and intelligent manipulation of the organized habits and opinions of the masses is an important element in democratic society. Those who manipulate this unseen mechanism of society constitute an invisible government which is the true ruling power of our country. ...We are governed, our minds are molded, our tastes formed, our ideas suggested, largely by men we have never heard of. This is a logical result of the way in which our democratic society is organized. Vast numbers of human beings must cooperate in this manner if they are to live together as a smoothly functioning society. ...In almost every act of our daily lives, whether in the sphere of politics or business, in our social conduct or our ethical thinking, we are dominated by the relatively small number of persons...who understand the mental processes and social patterns of the masses. It is they who pull the wires which control the public mind.'

https://en.wikipedia.org/wiki/Edward_Bernays#Philosophy