That was my take as well when I read "To fund construction of a new U.S. border wall," as if it was a given.
We are already supposed to be building a wall for a lot of the border, it is law and there was money.
On the other hand, we aren’t going to build a solid wall on our border.
First, because building a 30-foot wall up to the beachhead makes no sense, people near the beach will just walk to the beach and swim around it. You could build it into the ocean, but it will be horribly expensive and won’t really stop anybody.
Second, because you can’t build a wall in the middle of the river. And you can’t build the wall on the Mexican side of the river, because that is mexican territory. And you don’t want to build the wall on our side of the river, because you will cut off our own access to a vital resource.
Where there isn’t a river involved, a wall would be a great thing — although more important is guards. Any wall can be breached, what makes the wall work is security watching it. Then the wall just needs to slow people down enough that security can get there and arrest them if they try to breach the wall.
Which means in a lot of places like the river, we don’t need a wall at all, just border patrols often enough that noody can send a boat across the river quicker than a security detail will come by and see them.