The wall won't work, all South American leaders have discovered dynamite for sure.
Being real if we want to put 5B into immigration, we need to hire more immigration judges as a start. They have to handle thousands of cases, and for many families who want to cross they have to wait weeks to months to come over. Some have so many they are just handing out approvals to try to make the process as fast as they can. Due the long waiting period, immigrants will resort to illegally crossing. If we had more judges to work with, more time can be given to each case to fully vet actual criminals, and send along families faster.