Eminent domain has historically been used for a public use, not a private use. Roads, railroads, and pipelines are public uses. A wall to secure the border would be a public use.
Condemning a neighbor’s property so I can use it for a swimming pool and picnic area is not a public use and should not be allowed under eminent domain. Condemning private property so I can put in an auto parts store is not a public use.
You get the distinction.
The question isn’t whether we get it, does Cruz get it? And the answer is, no.