Can you explain why Republicans want to enforce border security with Mexico but not maritime borders with Cuba?

Cocaine is harvested and produced in southamerica only. and it enters to the USA by sea, air or land. The U.S is the country with the highest comber of drug addicts, and many of them are h0,mos. Florida is full of h0,mos and crack heads, it is a good market for the Mexican mafiosi.