Why do Republicans want so badly to close the Mexico-U.S border and open the Cuba-Florida maritime border?

hundreds of miles of land borders with Mexico, and hundred of miles of seashores in Florida just few miles away from the corrupt caribbean islands. Cocaine from southamerica is smuggled to the U.S through many routes, so why are Republicans ignoring some routes and obsessively picking on other routes? weird! it seems like republicans are laundering drug money in Florida! what would happen if the unorganized crime target those banks serving the organized crime?