1. That money was dwarfed by the cost of covering farmers losses for the retaliatory tariffs and and the tax cuts. There is less money to go around. 2. Since we were already dealing with Mexico under NAFTA, there will be little change. 3. It's like reinstalling a home security system for a 160-acre pasture you own. Expensive, easy to circumnavigate, not durable, and the wrong tool for the job. 4. Illegal immigrants make money for the country. Many of them come for a couple of decades, pay taxes, send a bunch of the remaining money home, and return to their home country to retire.