Deep state is state within a state. These are entities with deep-rooted and far-fetched interests in the way governments operate. These elements sabotage democratic instruments of the state to advance its interests.
An illustrative example is the military in Pakistan. The military is so powerful and the civil governments so weak in Pakistan that civil government tries to appease the military whenever it is in trouble. Politicians seek advice from the army chief in all critical matters of state. This happens even if the army chief was appointed by the civilian government, and that the government has chosen a particularly meek official for the post. But once the person becomes the army chief, he rises in valor and easily overshadows the prime minister. The army runs commercial enterprises, corporation and real estate behemoth such that it has deeply entrenched interests in the policies of the civil government. On crucial foreign policy decisions, especially related to India, it demands that government seeks it advice. The government will not dare to interfere with its interests, and it allows only those parties that follow its dictates. It is a state within a state. Whoever is the figure-head civilian leader.
The interests of the deep state elements run through generations and across parties. They would wedge their interests irrespective of who comes to power. If a particular person clearly inimical to the interest of the deep state comes to power, they will unleash their instruments of influence to silence the person.
In India, unlike in Pakistan, military did not grow as a ‘deep state ‘ element because our founding fathers like Nehru and Patel made well-calculated plans to cut such tendencies emerging. A detailed description of how military was made subordinate of the elected governments is described in the book Army and Nation by Steven Wilkinson -.https://www.amazon.in/Army-Nation-Military-Democracy-Independence/dp/0674728807.
However, certain unscrupulous business elements have replaced as the ‘deep state’ element in India. A clear party is the business conglomerate Reliance industries.
Reliance has rigged every level of governance that no one speaks against them. Reliance has brought all the media companies in India such that there is no tenable media house to articulate a position contrary to its interests. An illustrative story is how reliance reacted to an uncharitable book written by Hamish MacDonald ( https://www.amazon.com/Polyester-Prince-Rise-Dhirubhai-Ambani/dp/1864484683 Dhirubhai Ambani https://indianvanguard.wordpress.com/2011/08/12/polyester-prince-the-real-story-of-dhirubhai-ambanibanned-in-india/
The Ambanis brought all the copies of the book such that nothing was left in the bookstores for the public. (https://thewire.in/32479/the-unhappy-prince-how-dhirubhai-ambani-buried-a-book/). Ambanis fund all the political parties such that no one speak against the group. This kind of across the board conflict of interests create scenarios for the development of entrenched ‘deep state’ in India.
Deep state portents doom for democracy, as the voices that rallies against it are rapidly neutralised. Deep state tend to create ‘bipartisan’ opinion in favor of its own interests. We have seen such entities destroy democracy in many illiberal democracies of the East and the West.