You're right Topper, people flow from poverty to wealth automatically, in physics it's called the law of mass action.
http://tinyurl.com/y3weas
Traffic between Cuba, the US, & Mexico is quite free flowing for that black market that knows how; always was and always will be.
The United Staes itself started out as a pirate nation, illegally shuttling goods from the Carribean to the north-eastern states, which England looked down on because they were missing out on their share of the coin, and prosecuted violators with extreme prejudice (when they could catch them). You think with all the drugs & money that come & go between Cuba, Mexico, & the US, a trade in people that restricted?