Illegal businesses can't run without political patronage. Because there will be competition between the businesses and one group will always try to take out the other (and vice versa). If you don't have any powerful people supporting you, then you won't be protected from the raids and the business will be closed down. This happens mostly in the developing nations, where large number politicians are corrupt.
When it comes to the illegal things, the owner will need support from the powerful corrupt officials to protect them from the other owner. The competition will be hard if the corrupt officials interfere with that business, and they will do everything to make sure the business is still running. This business will never stop if it can not catch the corrupt officials. It needs more attention from the honest officials to investigate and search for that illegal casino.
Lol why need to bribe when they are already the authority?because most of them are run by officials or have family member that authority.
There are many cases here related to that,when the gambling place was raided then it comes out the owner is Big fish.
Some illegal casino that doesn't bond to that officials will bribe that person to get their support, which is not a secret. But maybe they will do the transaction by secretly without anyone knows. Sometimes, the illegal casino will belong to the corrupt officials, so they will get catch too if that place is raided.
With high official involvement that is the only reason that such things can operate very much inspite being illegal. Also the gamblers would be VIP and high rollers I feel so due to which so much billions worth of bets were handled during their time. Seems somebody from them only would have tipped or got them busted.
Sometimes, those high officials can have a meeting to make a plan or expand their business. Besides the illegal casino, they will try to create new illegal things such as drug dealers. Those people will give the best for the VIP, which has a lot of money because they can use big money for one round when they gamble. Sometimes, the casino gives a gift to them to make them satisfied with their services.