There is some very good high tech security that would accomplish this, perhaps for something closer to the amount already appropriated by Congress---something like $700 million. In the case of the caravan, this was informally announced anyway, giving us an opportunity to get the military and added CBP there.
https://www.reuters.com/article/us-u...-idUSKCN0XP28J

Border security Expo in San Antonio, TX:https://www.youtube.com/watch?v=xRM46Jkmrow

The overlooked part of our immigration policy is that we are still allowing advocay for illegals to go on almost unchecked.

Asking for this pie-in-the-sky project---and meanwhile conceding in several other areas---is not going to get us anywhere.