The boundary between US and Mexico is 1954 miles.
If I arbitrary set 195.4 miles as the length of the Trump wall that
actually gets built in the next 7 years, would you bet the over or under?
Let's set the requirement to meet qualification as Trump's Wall to simply its height specification of at least 18 feet.
'Physically imposing': Here are the design specs for Trump's border wall
Well I take the under--

They've already found 240 tunnels in the San Diego Region alone, and they know there's more.
The ins and outs of U.S.-Mexico border tunnels
I thought it was supposed to be 40' high, now it's 18 feet---

I have 24' extension ladder.
The only way to secure the border is with high tech motion detectors and more border patrol stations that can respond quickly. Anything they can see, can and will always be compromised. Something they can't see they won't even attempt to cross.
You know we can put a man on the moon--and we can't secure the border.
Or maybe it's they really don't want to secure the border, and just want to blow money on worthless walls and fences and pretend like they're doing something. Then they'll have something they can campaign on next Presidential election cycle.