Build the fence. Have manned towers every couple of miles. Have support for those manned towers every 8 miles. Have military bases every 50 miles, or so.
No more immigration problems.
A few machine guns might help...
Need new branch of military—The Border Guard—(like Coast Guard on Land) Only Job guard a 5 mile strip of land on our borders—They should have aircraft, armored cars, forts, horses, what ever it takes to man the wall and keep it secure. If people shoot at them—they should shoot back.