"And then there is that annoying little detail that some of the land that Texas needs to complete the wall is federally owned."

No, "all of it" is federally owned, and has been since WWII. The federal government owns a 60 ft swath of land bordering all international waters and borders. Abbot can build whatever his people are willing to pay for inside that zone and around any larger areas of federal property and Native reservations.

However, the wall doesn't have the majority support of landowners as Trump suggested. Some have suggested that a study revealed less than 25% of landowners on the southern border want a wall, or any barrier. Many of those are of Mexican descent who have owned their land since we expanded our border to encompass them.