Well, then I don’t know. It is an interstate project and maybe that might allow federal interference. I really don’t know. The Keystone pipeline may come under the heading of a utility which is a public purpose.
But people are changing the issue in this question here aren’t they? The issue that was brought up was Trump getting eminent domain to have a parking lot built for his casino, not unlike the unconstitutional Kelso decision where it was clear the benefit was for a PRIVATE purpose, not a PUBLIC purpose.
You have to go back to the original ruling by the USSC to see how it is to work outside the realm of public use but you have to define “public”. It’s much to complex to explain.