Perhaps the TVA will come later. At least this is a start. The current proposal limits the sale to $800,000,000 worth of land, with the proceeds to go to rural schools. In addition, the sale of the land will return it to the tax rolls, allowing a stream of cash into the counties and States in which the land is located.
Here in Southern Illinois, the Shawnee National Forest occupies large parts of many counties, as much as 75% of some of them. The landowners holding taxable properties in these counties must pay higher taxes in order to make up for the lost revenue due to public ownership of those lands.
The Constitution allows the government to acquire lands for needful facilities. Somehow we have determined that idle properties are needful, or that the government should own land it doesn't need and lease it at less than market value.
Quod scripsi, scripsi.