Today the most common way is sweetheart deals. A construction company will make a deal with a mobbed up union where they don't have to use more expensive union labor. That means their costs are lower, which gives them an advantage in winning a contract bid. In return for not having to use union labor, they hire mob members and associates on the books, but in reality they are no show jobs. This gives the mobsters and their cronies a legitimate source of income, health benefits, etc. It's a win-win deal for both sides, except of course for the honest dues-paying members of the union get screwed.