The Department of Homeland Security announced that the Biden administration leveraged sweeping executive power to waive 26 federal laws in South Texas.
Found this. Basically the claim here is that funds were allocated to this project, and although some of those funds were redirected, congress never deallocated the rest, and therefore they have to continue to be used. I’m not totally convinced but it’s a more nuanced take than the comments here.
This was my guess as well but neither the linked source nor any other one I can find explain exactly why he did it.
https://www.washingtontimes.com/news/2023/jun/30/joe-biden-forced-build-donald-trumps-border-wall/
Found this. Basically the claim here is that funds were allocated to this project, and although some of those funds were redirected, congress never deallocated the rest, and therefore they have to continue to be used. I’m not totally convinced but it’s a more nuanced take than the comments here.