I would think the cartels have the juice to move most of their products through ports of entry.
The entities controlling the Uniparty are committed to erasing national borders and basically creating a global version of the EU on steroids. The Wall is a giant turd in their punchbowl.
The cartels have to infiltrate police and border agencies to successfully use ports of entry. That is where the politicians play their role. Getting the cartels people into key positions.