I think if you go digging into these political families you will find many are somehow profiting from the WOD - laundering money, shipping contraband, taking bribes from the larger organized crime players.
For example here in Mass. a few years ago our US Rep. Congressman Tierney was discovered to be laundering money for offshore gambling casinos. It makes sense, big politicians and law enforcers can take advantage of being above the law. Send the cash off to your UBS Swiss bank account.
And of course many political families like the Kennedys made a fortune after the feds banned alcohol in the 1920's. Another recent example would be the ocean freighter owned by Mitch McConnell's family being busted for shipping cocaine up from Colombia.