Securing the border by itself is never gonna work:
- Making the border secure enough to stop all crossers would be prohibitively expensive, considering the length involved. Think of all the walls involved, the number of border patrol agents, the detention centers, the transportation system to send crossers back, etc. It's gonna be like financing a war.
- Never underestimate the strength of the human spirit. If I'm a parent living in abject poverty, watching my children eat shit every day, and knowing some will probably be shot dead by criminals/rebels/corrupt governments, I'd brave the border too to give them a better life. Many of your parents did just that.
- Most undocumented people probably came here with a visa. The most secure border in the world with high walls and laser turrets is not gonna stop people who are invited to walk through the gate.
The solution must involve easy path to legalization to those willing to work hard for it.