I honestly don't believe they ever considered getting caught, certainly not shut down on such a scale. They enter politics and/or the bureaucracy, then enticed with money, then either blackmailed or gleefully complicit in keeping their crime and that of their colleagues hidden til they leave office or die in office. As they indoctrinate each new member, they repeat the process, ensuring the secret perpetuates itself. Those that don't go along with the program are shunned, set up for an ignomious fall, or viciously attacked with baseless claims. It's one of many reasons they despise President Trump so much. He's rich enough that he can't be bought. Strong enough that he can't be broken. Smart enough that he's generally four moves ahead of them.