There needs to be real Port Security, and the vaunted, consolidated "Department of Homeland Security" should make it a fast reality. I'd, personally, rather have the government spend the enormous sums spent on the TSA spent on the Ports, along with additional funding for real border security.
If you try port security in Miami it would ruin the local economy. Without illicit trade the economy would collapse. Do you set up a protocol that prevents WMD but looks the other way at all the other crap that goes on? I'd like to see that.
The only solution is to infiltrate and kill the terrorist. There is not a net or wall that will stop them.